kbuild: Allow architectures to change CPPFLAGS

In some cases (notably ia64) changes to CPPFLAGS is needed, and
relevant both for AS and CC. Make sure changes to CPPFLAGS propagate
back to CFLAGS and AFLAGS

Makefile

@@ -223,9 +223,9 @@ AFLAGS_KERNEL	=
 NOSTDINC_FLAGS  = -nostdinc -iwithprefix include
 
 CPPFLAGS	:= -D__KERNEL__ -Iinclude
-CFLAGS 		:= $(CPPFLAGS) -Wall -Wstrict-prototypes -Wno-trigraphs -O2 \
+CFLAGS 		:= -Wall -Wstrict-prototypes -Wno-trigraphs -O2 \
 	  	   -fno-strict-aliasing -fno-common
-AFLAGS		:= -D__ASSEMBLY__ $(CPPFLAGS)
+AFLAGS		:= -D__ASSEMBLY__
 
 export	VERSION PATCHLEVEL SUBLEVEL EXTRAVERSION KERNELRELEASE ARCH \
 	CONFIG_SHELL TOPDIR HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC \
@@ -281,6 +281,10 @@ endif
 
 include arch/$(ARCH)/Makefile
 
+# Let architecture Makefiles change CPPFLAGS if needed
+CFLAGS += $(CPPFLAGS) $(CFLAGS)
+AFLAGS += $(CPPFLAGS) $(AFLAGS)
+
 core-y		+= kernel/ mm/ fs/ ipc/ security/ crypto/
 
 SUBDIRS		+= $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \

arch/ia64/Makefile

@@ -27,9 +27,8 @@ GCC_MINOR_VERSION=$(shell $(CC) -v 2>&1 | fgrep 'gcc version' | cut -f3 -d' ' |
 
 GAS_STATUS=$(shell arch/ia64/scripts/check-gas $(CC) $(OBJDUMP))
 
-arch-cppflags	:= $(shell arch/ia64/scripts/toolchain-flags $(CC) $(LD) $(OBJDUMP))
-cflags-y	+= $(arch-cppflags)
-AFLAGS		+= $(arch-cppflags)
+CPPFLAGS	+= $(shell arch/ia64/scripts/toolchain-flags \
+				$(CC) $(LD) $(OBJDUMP))
 
 ifeq ($(GAS_STATUS),buggy)
 $(error Sorry, you need a newer version of the assember, one that is built from	\