arm: armv7: add compile option -mno-unaligned-access if available

Recent compiler generates unaligned memory access in armv7 default.
But current U-Boot does not allow unaligned memory access, so it causes
data abort exception.
This patch add compile option "-mno-unaligned-access" if it is available.

Signed-off-by: Tetsuyuki Kobayashi <koba@kmckk.co.jp>
Tested-by: Gary Thomas <gary@mlbassoc.com>

arch/arm/cpu/armv7/config.mk

@@ -26,6 +26,8 @@ PLATFORM_RELFLAGS += -fno-common -ffixed-r8 -msoft-float
 # supported by more tool-chains
 PF_CPPFLAGS_ARMV7 := $(call cc-option, -march=armv7-a, -march=armv5)
 PLATFORM_CPPFLAGS += $(PF_CPPFLAGS_ARMV7)
+PF_CPPFLAGS_NO_UNALIGNED := $(call cc-option, -mno-unaligned-access,)
+PLATFORM_CPPFLAGS += $(PF_CPPFLAGS_NO_UNALIGNED)
 
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