build: break compiler flags out of $(CC)

Having more than the executable in $(CC) only leads to
trouble in a number of situations.

Change-Id: I7642ca4068b3a3bd5798219d74de9e0eb85bb4e5
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-on: http://review.coreboot.org/5769
Tested-by: build bot (Jenkins)
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>

src/arch/x86/Makefile.inc

@@ -28,7 +28,7 @@ subdirs-y += lib
 subdirs-y += smp
 
 ifeq ($(CONFIG_COMPILER_GCC),y)
-DISASSEMBLY=-Wa,-acdlns
+DISASSEMBLY=-Wa,-acdlns $(CFLAGS_x86_32)
 else
 DISASSEMBLY=
 endif

toolchain.inc

@@ -25,7 +25,7 @@ ARCHDIR-i386    := x86
 ARCHDIR-x86_32  := x86
 ARCHDIR-armv7   := armv7
 
-CFLAGS_armv7 = \
+CFLAGS_armv7 += \
 	-ffixed-r8\
 	-march=armv7-a\
 	-marm\
@@ -35,7 +35,7 @@ CFLAGS_armv7 = \
 
 toolchain_to_dir = \
 	$(foreach arch,$(ARCH_SUPPORTED),\
-	$(eval CPPFLAGS_$(arch) = \
+	$(eval CPPFLAGS_$(arch) += \
 	-Isrc/arch/$(ARCHDIR-$(arch))/include))
 
 # set_stage_toolchain: Decides the toolchain to be used by every stage

util/xcompile/xcompile

@@ -147,7 +147,8 @@ detect_special_flags() {
 report_arch_toolchain() {
 	cat <<EOF
 # elf${TWIDTH}-${TBFDARCH} toolchain (${GCCPREFIX}gcc)
-CC_${TARCH}:=${GCCPREFIX}gcc ${CFLAGS}
+CC_${TARCH}:=${GCCPREFIX}gcc
+CFLAGS_${TARCH}:=${CFLAGS}
 CPP_${TARCH}:=${GCCPREFIX}cpp
 AS_${TARCH}:=${GCCPREFIX}as ${ASFLAGS}
 LD_${TARCH}:=${GCCPREFIX}ld${LINKER_SUFFIX} ${LDFLAGS}