cbmem: Fix makefile

The .dependencies rule did not use the CPPFLAGS variable which led
to funny behavior: a spurious termination message the first time
(after checkout/make distclean) one executes make. Afterwards the
(wrongly) empty .dependencies file hides the problem and the binary
is created anyway.

$ make
cbmem.c:37:34: fatal error: boot/coreboot_tables.h: No such file or directory
compilation terminated.
cc -O2 -Wall -Werror -iquote ../../src/include -iquote ../../src/src/arch/x86  -c -o cbmem.o cbmem.c
cc   cbmem.o   -o cbmem

$ make
make: Nothing to be done for `all'.

$ make clean
rm -f cbmem *.o *~

$ make
cc -O2 -Wall -Werror -iquote ../../src/include -iquote ../../src/src/arch/x86  -c -o cbmem.o cbmem.c
cc   cbmem.o   -o cbmem

$ make distclean
rm -f cbmem *.o *~
rm -f .dependencies

$ make
cbmem.c:37:34: fatal error: boot/coreboot_tables.h: No such file or directory
compilation terminated.
cc -O2 -Wall -Werror -iquote ../../src/include -iquote ../../src/src/arch/x86  -c -o cbmem.o cbmem.c
cc   cbmem.o   -o cbmem

I fixed that by adding the CPPFLAGS variable to the .dependencies recipe, just
like Stefan Reinauer did in Chromium (Ia9d2e10a3ef122f30d681d16c2291eb108ead835),
hence the split sign-off for this tiny change. :)

Change-Id: Icd11b146ad762cbdf9774630b950f70e1253a072
Signed-off-by: Stefan Reinauer <reinauer@google.com>
Signed-off-by: Stefan Tauner <stefan.tauner@gmx.at>
Reviewed-on: http://review.coreboot.org/3548
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins)
Reviewed-by: Nico Huber <nico.huber@secunet.com>

util/cbmem/Makefile

@@ -37,7 +37,7 @@ distclean: clean
 	rm -f .dependencies
 
 .dependencies:
-	@$(CC) $(CFLAGS) -MM *.c > .dependencies
+	@$(CC) $(CFLAGS) $(CPPFLAGS) -MM *.c > .dependencies
 
 .PHONY: all clean distclean