servo_v4: use coreboot toolchain
This defaults servo_v4 to use the more compact coreboot
toolchain, as the flash is full.
BRANCH=None
TEST=still works
CHIP:=stm32
CHIP_FAMILY:=stm32f0
CHIP_VARIANT:=stm32f07x
+$(call set-option,CROSS_COMPILE_arm,$(CROSS_COMPILE_arm),\
+ /opt/coreboot-sdk/bin/arm-eabi-)
# Not enough SRAM: Disable all tests
test-list-y=
