ARM: 8588/1: localise objcopy flags

We currently define OBJCOPYFLAGS in the top-level arm Makefile, and thus
these flags will be passed to all uses of objcopy, kernel-wide, for
which they are not explicitly overridden. The flags we set are intended
for converting a few ELF files into raw binaries, and thus the flags
chosen are problematic for some other uses which do not expect a raw
binary result, e.g. the upcoming lkdtm rodata test:

http://www.openwall.com/lists/kernel-hardening/2016/06/08/2

This patch localises the objcopy flags such that they are only used for
the cases we require them for today.

Signed-off-by: Mark Rutland <[e-mail]>
Acked-by: Kees Cook <[e-mail]>
Tested-by: Laura Abbott <[e-mail]>
Cc: Russell King <[e-mail]>
Signed-off-by: Russell King <[e-mail]>

arch/arm/Makefile

···
 LDFLAGS_MODULE	+= -T $(srctree)/arch/arm/kernel/module.lds
 endif
 
-OBJCOPYFLAGS	:=-O binary -R .comment -S
 GZFLAGS		:=-9
 #KBUILD_CFLAGS	+=-pipe
 

arch/arm/boot/Makefile

···
 # Copyright (C) 1995-2002 Russell King
 #
 
+OBJCOPYFLAGS	:=-O binary -R .comment -S
+
 ifneq ($(MACHINE),)
 include $(MACHINE)/Makefile.boot
 endif