kbuild: fix up CFLAGS usage

Only in very rare cases is it needed to change CFLAGS
outside of arch/*/Makefile.
Fix up all wrong cases - in most cases
the use of EXTRA_CFLAGS is the only thing needed.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

arch/parisc/math-emu/Makefile

@@ -3,7 +3,7 @@
 #
 
 # See arch/parisc/math-emu/README
-CFLAGS += -Wno-parentheses -Wno-implicit-function-declaration \
+EXTRA_CFLAGS += -Wno-parentheses -Wno-implicit-function-declaration \
 	-Wno-uninitialized -Wno-strict-prototypes -Wno-return-type \
 	-Wno-implicit-int
 

arch/ppc/boot/Makefile

@@ -13,7 +13,6 @@
 # modified by Cort (cort@cs.nmt.edu)
 #
 
-CFLAGS	 	+= -fno-builtin -D__BOOTER__ -Iarch/$(ARCH)/boot/include
 HOSTCFLAGS	+= -Iarch/$(ARCH)/boot/include
 
 BOOT_TARGETS	= zImage zImage.initrd znetboot znetboot.initrd

arch/x86/math-emu/Makefile

@@ -5,8 +5,7 @@
 #DEBUG	= -DDEBUGGING
 DEBUG	=
 PARANOID = -DPARANOID
-CFLAGS	:= $(CFLAGS) $(PARANOID) $(DEBUG) -fno-builtin $(MATH_EMULATION)
-
+EXTRA_CFLAGS	:= $(PARANOID) $(DEBUG) -fno-builtin $(MATH_EMULATION)
 EXTRA_AFLAGS	:= $(PARANOID)
 
 # From 'C' language sources:

arch/xtensa/boot/Makefile

@@ -8,13 +8,12 @@
 #
 
 
-CFLAGS 		+= -fno-builtin -Iarch/$(ARCH)/boot/include
+EXTRA_CFLAGS	+= -fno-builtin -Iarch/$(ARCH)/boot/include
 HOSTFLAGS	+= -Iarch/$(ARCH)/boot/include
 
 BIG_ENDIAN	:= $(shell echo -e __XTENSA_EB__ | $(CC) -E - | grep -v "\#")
 
-export CFLAGS
-export AFLAGS
+export EXTRA_CFLAGS
 export BIG_ENDIAN
 
 subdir-y	:= lib