 the previous version with the following commands:
Remove the 1001 version from the system:
apt remove linux-image-5.4.0-1011-raspi 

Reinstall the previous version of kernel, modules and headers:
apt-get install --reinstall linux-image-5.4.0-1008-raspi
apt-get install --reinstall linux-headers-5.4.0-1008-raspi
apt-get install --reinstall  linux-modules-5.4.0-1008-raspi

I rebooted successfully the PI4 with the previous kernel version. The next step is to exclude the kernel from updates until the problem is fixed:
apt-mark hold linux-image-5.4.0-1008-raspi
apt-mark hold linux-headers-5.4.0-1008-raspi
apt-mark hold linux-modules-5.4.0-1008-raspi

Afterwards you can remove the unused kernel version:
apt remove linux-raspi-headers-5.4.0-1011

# after a reboot:
pi04:~/.ssh# uname -a
Linux pi04 5.4.0-1008-raspi #8-Ubuntu SMP Wed Apr 8 11:13:06 UTC 2020 aarch64 aarch64 aarch64 GNU/Linux

# to clean up the system the 1011 headers and modules can be removed

apt remove linux-headers-5.4.0-1011-raspi
apt remove linux-modules-5.4.0-1011-raspi

from your system.
My installation history for the system: 
Filename: /var/log/apt/history.log

Start-Date: 2020-05-22  09:51:29
Commandline: apt upgrade
Install: linux-headers-5.4.0-1011-raspi:arm64 (5.4.0-1011.11, automatic), linux-modules-5.4.0-1011-raspi:arm64 (5.4.0-1011.11, automatic), linux-image-5.4.0-1011-raspi:arm64 (5.4.0-1011.11, automatic), linux-raspi-headers-5.4.0
the previous version with the following commands: 
 Remove the 1001 interpretation from the arrangement: 
 apt remove linux - image-5.4.0 - 1011 - raspi 

 Reinstall the previous version of kernel, module and headers: 
 apt - get install --reinstall linux - image-5.4.0 - 1008 - raspi 
 apposite - get install --reinstall linux - headers-5.4.0 - 1008 - raspi 
 apt - get install --reinstall   linux - modules-5.4.0 - 1008 - raspi 

 I rebooted successfully the PI4 with the previous kernel adaptation. The next step is to eject the kernel from updates until the problem is specify: 
 apt - mark hold linux - image-5.4.0 - 1008 - raspi 
 apt - mark hold linux - headers-5.4.0 - 1008 - raspi 
 apposite - mark hold linux - modules-5.4.0 - 1008 - raspi 

 Afterwards you can take out the unused kernel version: 
 apposite remove linux - raspi - headers-5.4.0 - 1011 

 # after a reboot: 
 pi04:~/.ssh # uname -a 
 Linux pi04 5.4.0 - 1008 - raspi # 8 - Ubuntu SMP We d Apr 8 11:13:06 UTC 2020 aarch64 aarch64 aarch64 GNU / Linux 

 # to clean up the organization the 1011 headers and module can be removed 

 apt remove linux - headers-5.4.0 - 1011 - raspi 
 apt remove linux - modules-5.4.0 - 1011 - raspi 

 from your arrangement. 
 My installation history for the system: 
 Filename: /var / log / apt / history.log 

 Start - Date: 2020 - 05 - 22   09:51:29 
 Commandline: apt upgrade 
 Install: linux - headers-5.4.0 - 1011 - raspi: arm64 (5.4.0 - 1011.11, automatic), linux - modules-5.4.0 - 1011 - raspi: arm64 (5.4.0 - 1011.11, automatic), linux - image-5.4.0 - 1011 - raspi: arm64 (5.4.0 - 1011.11, automatic), linux - raspi - headers-5.4.0
 thf previous version with uhe following commands:
Rekove tge 1001 verskon from the system:
apt removx libux-imqge-5.4.0-1011-raspi 

Reinstall the previous version of jwrnel, modules and mzadera:
wpt-gzt install --reinsjall linux-imdge-5.4.0-1008-raspi
apt-get ivscall --reinstall linux-headers-5.4.0-1008-raspi
apt-gqt instslp --reinstall  lynux-kjdulss-5.4.0-1008-raspi

I rebooted successfully the PI4 witi the previous lernel version. The next stfp id to exclude the kfrnel from oldaews until the problem is fixed:
apt-matk hold linux-image-5.4.0-1008-raspi
apt-mark huld lnnux-headers-5.4.0-1008-tcwpi
wkt-mark hold oinux-iodules-5.4.0-1008-raspi

Afterwargs you van remove the unnsed kernel version:
apt rekove linux-raspi-heaqers-5.4.0-1011

# aftes c reboot:
pi04:~/.ssh# uname -a
Oibux ph04 5.4.0-1008-ravpi #8-Jvungu AM' Wsd Apr 8 11:13:06 NTC 2020 aarch64 zarch64 aarch64 GNU/Linux

# to clean ip nne system ths 1011 heaqews and modules can be removed

apt remove lihux-headers-5.4.0-1011-raspi
apt remoce linux-modules-5.4.0-1011-raspi

ftom your srstem.
My installation history for the system: 
Filendme: /ver/uog/cib/hisgirj.log

Start-Date: 2020-05-22  09:51:29
Commandline: apt upgrade
Instalj: lonlx-headers-5.4.0-1011-raspi:arm64 (5.4.0-1011.11, automatic), llniv-modules-5.4.0-1011-raspi:xrm64 (5.4.0-1011.11, abfojatic), linux-image-5.4.0-1011-radpi:arm64 (5.4.0-1011.11, autonatic), lintx-raxpi-headers-5.4.0
the previous version with the following commands: 1001 from the apt remove linux-image-5.4.0-1011-raspi kernel, and headers: apt-get --reinstall linux-image-5.4.0-1008-raspi apt-get --reinstall linux-headers-5.4.0-1008-raspi apt-get install --reinstall linux-modules-5.4.0-1008-raspi rebooted successfully the PI4 with the previous kernel version. The next step is exclude the kernel from updates until the problem is fixed: apt-mark hold linux-image-5.4.0-1008-raspi hold apt-mark linux-modules-5.4.0-1008-raspi you can remove the unused kernel version: apt remove linux-raspi-headers-5.4.0-1011 # after a reboot: pi04:~/.ssh# uname Linux pi04 5.4.0-1008-raspi #8-Ubuntu SMP Wed Apr 8 UTC 2020 aarch64 aarch64 GNU/Linux # to clean up system 1011 headers modules be apt remove linux-headers-5.4.0-1011-raspi remove linux-modules-5.4.0-1011-raspi from your system. My installation history for the system: Filename: /var/log/apt/history.log Start-Date: 2020-05-22 09:51:29 Commandline: upgrade Install: automatic), linux-modules-5.4.0-1011-raspi:arm64 automatic), (5.4.0-1011.11, linux-raspi-headers-5.4.0
 the previous version with the Following cOmmanDs:
REmoVe The 1001 vErsiOn from the systeM:
Apt rEmove linux-image-5.4.0-1011-raspi 

ReInstaLl THe prEViOus veRsion of KErNEL, moDuLeS anD hEAdErs:
apT-geT instalL --reinstall LinUx-Image-5.4.0-1008-raspi
apT-GeT install --reInsTall linux-heaDerS-5.4.0-1008-raspi
ApT-geT InstaLl --rEinstAll  linUX-modulEs-5.4.0-1008-raspi

I rEbOOted suCCessfulLY ThE PI4 wIth the previous kerNEl VErsion. The next sTep is tO eXClUDE thE keRnel from upDaTes unTIl the prOBlEM IS fiXEd:
apt-mark hold Linux-image-5.4.0-1008-rASpi
Apt-marK hOld LInux-heAders-5.4.0-1008-RaSPi
aPt-mark hold lInux-Modules-5.4.0-1008-raSpi

AftERwards yOU can remOve the UnuSed KernEL vErSioN:
aPT reMOvE liNUx-rAspi-headErS-5.4.0-1011

# aFter a ReboOT:
PI04:~/.Ssh# uNamE -a
LiNux pi04 5.4.0-1008-Raspi #8-Ubuntu SMp WeD Apr 8 11:13:06 utC 2020 aArch64 aArch64 aArch64 gNu/LinuX

# to cleAn up tHe System the 1011 headerS and Modules caN be ReMovEd

Apt reMOve linUx-hEadErs-5.4.0-1011-raspI
apt remOVe lInUX-MOdUles-5.4.0-1011-raspi

from your sYsTEM.
MY installAtion hIStOrY For the syStEm: 
FIlenAME: /var/lOg/apT/HiStory.log

start-DATe: 2020-05-22  09:51:29
coMmandliNe: Apt upgRaDe
INstAll: liNUx-heAders-5.4.0-1011-rAspi:arm64 (5.4.0-1011.11, aUtomaTIc), linux-modules-5.4.0-1011-RAspi:arm64 (5.4.0-1011.11, automaTIc), LINuX-ImagE-5.4.0-1011-raSpi:arm64 (5.4.0-1011.11, automAtic), LInux-RaspI-HeAdeRS-5.4.0
 the previous version with  the follo wingcom man ds :
Re move  the 1001 vers i on f rom the system:
apt re moveli n ux-i m ag e-5.4 .0-1011 - ra s p i 
R ei nst al l  t he pr evi ous ver sion of ke rne l,  modules and he aders:
apt -ge t install -- rei nstall  l inu x -imag e-5 .4.0- 1008-r a spi
ap t-get ins ta l l --re i nstalll i nu x-he aders-5.4.0-1008- r as p i
apt-get inst all -- re i ns t a ll li nux-module s- 5.4.0 - 1008-ra s pi I  re b ooted success fully the P I 4 w ith th epre v ious k ernel  v e rsi on. The nex t st ep is toexclud e  the ke r nel fro m upda tes  un tilt he  p rob le m  is fi xed : 
ap t-mark h ol dlinux -ima g e - 5 .4.0 -10 08-r aspiapt-mark hold  li nux- h ead ers-5 .4.0- 1008 -r aspiapt-ma rk ho ld  linux-modules- 5.4. 0-1008-ra spi 
Aft er wards you ca n r emo ve theunusedk ern el v e rs ion:
apt remove li nu x - ra spi-head ers-5. 4 .0 -1 0 11

# af te r a  reb o o t:
pi 04:~ / .s sh# unam e -a
L i nu xpi04 5. 4. 0-1008 -r asp i # 8-Ubu n tu S MP Wed  Apr 8 1 1:13: 0 6 UTC 2020 aar c h64 aarch64 a a rc h 6 4G NU/L inu x

# to cle an u p  the  sys t em  th e  1011  head er s  a n d modules can be re mo ved

a pt re move linux-he aders-5.4. 0 - 1 011-rasp i
ap t  r e move linux-mod ules- 5.4.0-1011 - raspi

f rom y our syst em.
My in s t allation  hi sto ryfor t he  system: 
Fil e n ame:  / var/log /ap t/histo ry. log 

S tar t- Date: 202 0-05-22 0 9: 51 :2 9
C omman d line: ap tupg ra deInsta l l: lin ux-he ader s- 5. 4 .0- 1011-ra s pi : a rm64  ( 5. 4.0- 101 1. 11, a utom a tic ), linu x-modules -5. 4 .0-1 01 1- raspi:a rm64 (5.4.0-1 01 1.11, auto ma tic ), lin u x -image-5 .4.0-1011-raspi:arm64 ( 5 .4.0-10 11. 11, a utom atic), li nux -raspi -he a ders-5 .4.0
 the_previous version_with the following commands:
Remove_the 1001_version_from the_system:
apt_remove linux-image-5.4.0-1011-raspi 

Reinstall_the previous version_of kernel, modules and_headers:
apt-get install --reinstall_linux-image-5.4.0-1008-raspi
apt-get_install --reinstall linux-headers-5.4.0-1008-raspi
apt-get install --reinstall  linux-modules-5.4.0-1008-raspi

I rebooted successfully the PI4 with the previous_kernel_version. The_next_step_is to exclude the kernel_from updates until the problem_is fixed:
apt-mark_hold linux-image-5.4.0-1008-raspi
apt-mark hold linux-headers-5.4.0-1008-raspi
apt-mark hold linux-modules-5.4.0-1008-raspi

Afterwards you can_remove_the unused kernel_version:
apt remove linux-raspi-headers-5.4.0-1011

# after a reboot:
pi04:~/.ssh# uname -a
Linux pi04_5.4.0-1008-raspi #8-Ubuntu SMP Wed Apr 8_11:13:06 UTC 2020_aarch64_aarch64_aarch64 GNU/Linux

# to clean_up the system the 1011 headers_and modules can be removed

apt remove_linux-headers-5.4.0-1011-raspi
apt remove linux-modules-5.4.0-1011-raspi

from your system.
My installation history_for the system: 
Filename: /var/log/apt/history.log

Start-Date: 2020-05-22_ 09:51:29
Commandline: apt upgrade
Install: linux-headers-5.4.0-1011-raspi:arm64_(5.4.0-1011.11, automatic),_linux-modules-5.4.0-1011-raspi:arm64 (5.4.0-1011.11, automatic), linux-image-5.4.0-1011-raspi:arm64 (5.4.0-1011.11,_automatic), linux-raspi-headers-5.4.0