[ATM]: Add CPPFLAGS to byteorder.h check

O= builds produced errors in the shell command because of unfound headers.
Signed-off-by: NBen Collins <bcollins@ubuntu.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/atm/Makefile

@@ -41,7 +41,7 @@ ifeq ($(CONFIG_ATM_FORE200E_PCA),y)
   # guess the target endianess to choose the right PCA-200E firmware image
   ifeq ($(CONFIG_ATM_FORE200E_PCA_DEFAULT_FW),y)
     byteorder.h			:= include$(if $(patsubst $(srctree),,$(objtree)),2)/asm/byteorder.h
-    CONFIG_ATM_FORE200E_PCA_FW	:= $(obj)/pca200e$(if $(shell $(CC) -E -dM $(byteorder.h) | grep ' __LITTLE_ENDIAN '),.bin,_ecd.bin2)
+    CONFIG_ATM_FORE200E_PCA_FW	:= $(obj)/pca200e$(if $(shell $(CC) $(CPPFLAGS) -E -dM $(byteorder.h) | grep ' __LITTLE_ENDIAN '),.bin,_ecd.bin2)
   endif
 endif