xtensa: change to new flag variable

Replace EXTRA_CFLAGS with ccflags-y.

Signed-off-by: matt mooney <mfm@muteddisk.com>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>

arch/xtensa/boot/Makefile

@@ -14,7 +14,7 @@ HOSTFLAGS	+= -Iarch/$(ARCH)/boot/include
 
 BIG_ENDIAN	:= $(shell echo -e __XTENSA_EB__ | $(CC) -E - | grep -v "\#")
 
-export EXTRA_CFLAGS
+export ccflags-y
 export BIG_ENDIAN
 
 subdir-y	:= lib

arch/xtensa/boot/lib/Makefile

@@ -6,7 +6,7 @@ zlib	:= inffast.c inflate.c inftrees.c
 
 lib-y	+= $(zlib:.c=.o) zmem.o
 
-EXTRA_CFLAGS	+= -Ilib/zlib_inflate
+ccflags-y	:= -Ilib/zlib_inflate
 
 quiet_cmd_copy_zlib = COPY    $@
       cmd_copy_zlib = cat $< > $@