Remove compiler warning: target CPU does not support interworking

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>

cpu/arm1136/config.mk

@@ -31,4 +31,5 @@ PLATFORM_CPPFLAGS += -march=armv5
 #
 # =========================================================================
 PLATFORM_CPPFLAGS +=$(call cc-option,-mapcs-32,-mabi=apcs-gnu)
+PLATFORM_CPPFLAGS +=$(call cc-option,-mno-thumb-interwork,)
 PLATFORM_RELFLAGS +=$(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,))