Kbuild: use local CFLAGS

Change-Id: I498fa7846bc84b146540f639753b71a724ec8fdb
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
diff --git a/Makefile.inc b/Makefile.inc
index 222955f..2098df9 100644
--- a/Makefile.inc
+++ b/Makefile.inc
@@ -27,7 +27,7 @@
 
 all: $(CONFIG_DEPS)
 	$(Q)$(MAKE) -C $(TIMO_BASE)  O=$(PROJECT_BASE) \
-	PROJECT=$(PROJECT_BASE) SOURCE_DIR=$(SOURCE_DIR)
+	PROJECT=$(PROJECT_BASE) SOURCE_DIR=$(SOURCE_DIR) CFLAGS=$(CFLAGS)
 
 rm-files:= final-linker.cmd linker.cmd modules.order \
 	staticIdt.o System.map *kernel.lnk \