pseries: Update SLOF firmware image to 20160223

The main change is virtio 1.0 support.

The complete changelog is:
  > dhcp: fix warning messages when calling strtoip()
  > virtio-scsi: enable virtio 1.0
  > virtio-scsi: use virtio_fill desc api
  > virtio-scsi: use idx during initialization
  > virtio-net: enable virtio 1.0
  > virtio-blk: enable virtio 1.0
  > virtio: 1.0 helper to read 16/32/64 bit value
  > virtio: add and enable 1.0 device setup
  > virtio: 1.0 guest features negotiation
  > virtio: update features set/get register accessor
  > virtio: make all virtio apis 1.0 aware
  > virtio: add 64-bit virtio helpers for 1.0
  > virtio: add virtio 1.0 related struct and defines
  > virtio: get rid of type variable in virtio_device
  > virtio-net: move setup-mac to the open routine
  > virtio-net: make net_hdr_size a variable
  > virtio-net: replace vq array with vq_{tx,rx}
  > virtio-net: use virtio_fill_desc
  > virtio-{net,blk,scsi,9p}: use status variable
  > virtio-blk: add helpers for filling descriptors
  > virtio-{blk,9p}: enable resetting the device
  > virtio: introduce helper for initializing virt queue
  > virtio: fix code style/design issues.
  > fix code style in byteorder.h
  > pci: add byte read/write helper routines
  > virtio-net: fix gcc warnings (-Wextra)
  > virtio-blk: fix gcc warnings (-Wextra)
  > readme: Add a note about coding style
  > dhcp: Remove duplicated strtoip()
  > ethernet: Fix gcc warnings
  > net-snk: Fix gcc warnings
  > net-snk: Fix coding style
  > net-snk: Fix memory leak in dhcp6_process_options()
  > net-snk: Fix memory leak in ip6_to_multicast_mac() / send_ipv6()
  > net-snk: Remove bad NEIGHBOUR_SOLICITATION code in send_ipv6()
  > Fix dma-alloc and dma-map-in functions on board-js2x
  > net-snk: Allow stateless autoconfig IPv6 addresses with IP_INIT_IPV6_MANUAL
  > net-snk: Simplify the ip6_is_multicast() function
  > net-snk: Move global variable definition out of the header file
  > net-snk: Prefer non-link-local unicast IPv6 addresses if possible
  > net-snk: Fix the check for link-local addresses when receiving RAs
  > net-snk: Remove junk at the end of IPv6 TFTP ACK and error packets
  > Fix format strings in usb-ohci.c
  > net-snk: Get rid of junk at the end of sent DHCPv6 packets
  > net-snk: Use transaction IDs in DHCPv4, too
  > net-snk: Make use of DHCPv6 transaction IDs
  > net-snk: Seed the pseudo-random number generator
  > libc: Add srand() call
  > libc: Fix the rand() function to return non-zero values
  > net-snk: Improve printed text when booting via network
  > Increase temporary buffer size of ibm,client-architecture-support call
  > Move archsupport.fs into board-qemu directory
  > boot: stop booting when we encounter HALT
  > fat-files: Fix bug with root-entries = 0 on certain FAT32 file systems
  > usb: print unhandled descriptor in debug mode
  > Improve stack usage with libnvram get_partition function
  > Improve stack usage in libnvram environment variable code
  > libc: Port vsnprintf back from skiboot
  > Move the code for rfill into a separate function
  > Rework wrapper for new_nvram_partition() and fix possible bug in there
  > Stack optimization in libusb: split up setup_new_device()
  > Check for stack overflow in paflof engine
  > Clean up pending packet variable in ipv4 code
  > Fix tracking of pending outgoing packets when handling ARP replies

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
