ARM: 8534/1: virt: fix hyp-stub build for pre-ARMv7 CPUs

ARMv6 CPUs do not have virtualisation extensions, but hyp-stub.S is
still included into the image to keep it generic. In order to use ARMv7
instructions during HYP initialisation, add -march=armv7-a flag to
hyp-stub's build.

On an ARMv6 CPU, __hyp_stub_install returns as soon as it detects that
the mode isn't HYP, so we will never reach those instructions.
Signed-off-by: NJean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

arch/arm/boot/compressed/Makefile

@@ -186,5 +186,7 @@ CFLAGS_font.o := -Dstatic=
 $(obj)/font.c: $(FONTC)
 	$(call cmd,shipped)
 
+AFLAGS_hyp-stub.o := -Wa,-march=armv7-a
+
 $(obj)/hyp-stub.S: $(srctree)/arch/$(SRCARCH)/kernel/hyp-stub.S
 	$(call cmd,shipped)

arch/arm/kernel/Makefile

@@ -88,6 +88,7 @@ obj-$(CONFIG_DEBUG_LL)	+= debug.o
 obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o
 
 obj-$(CONFIG_ARM_VIRT_EXT)	+= hyp-stub.o
+AFLAGS_hyp-stub.o		:=-Wa,-march=armv7-a
 ifeq ($(CONFIG_ARM_PSCI),y)
 obj-$(CONFIG_SMP)		+= psci_smp.o
 endif