[POWERPC] Add -fno-stack-protector to BOOTCFLAGS in arch/powerpc/boot/Makefile.

I got some undefined references to __stack_chk_fail in
arch/powerpc/boot/stdio.o and arch/powerpc/boot/prom.o when I was trying
to build a kernel on Ubuntu Edgy Eft - which includes Stack Smashing
Protection.

This patch adds -fno-stack-protector to BOOTCFLAGS in
arch/powerpc/boot/Makefile (why does BOOTCFLAGS depend on HOSTCFLAGS and
not CFLAGS?).

Regards,
Niels Kristian Bech Jensen
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/boot/Makefile

@@ -41,6 +41,10 @@ src-boot += $(zlib)
 src-boot := $(addprefix $(obj)/, $(src-boot))
 obj-boot := $(addsuffix .o, $(basename $(src-boot)))
 
+ifeq ($(call cc-option-yn, -fstack-protector),y)
+BOOTCFLAGS	+= -fno-stack-protector
+endif
+
 BOOTCFLAGS	+= -I$(obj) -I$(srctree)/$(obj)
 
 quiet_cmd_copy_zlib = COPY    $@