[Blackfin] arch: declare CHECKFLAGS to make sparse output more readable

KBUILD_CFLAGS += -mcpu=$(cpu-y)-$(rev-y)

KBUILD_AFLAGS += -mcpu=$(cpu-y)-$(rev-y)

# - we utilize the silicon rev from the toolchain, so move it over to the checkflags

# - the l1_text attribute is Blackfin specific, so fake it out as used to kill warnings

CHECKFLAGS_SILICON = $(shell echo "" | $(CPP) $(KBUILD_CFLAGS) -dD - 2>/dev/null | awk '$$2 == "__SILICON_REVISION__" { print $$3 }')

CHECKFLAGS += -D__SILICON_REVISION__=$(CHECKFLAGS_SILICON) -Dl1_text=__used__

head-y   := arch/$(ARCH)/mach-$(MACHINE)/head.o arch/$(ARCH)/kernel/init_task.o

core-y   += arch/$(ARCH)/kernel/ arch/$(ARCH)/mm/ arch/$(ARCH)/mach-common/