portmap: respect target CFLAGS

Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

package/portmap/portmap.mk

@@ -15,6 +15,7 @@ PORTMAP_FLAGS += NO_FORK=1
 endif
 
 define PORTMAP_BUILD_CMDS
+	CFLAGS="$(TARGET_CFLAGS)" \
 	$(MAKE) CC="$(TARGET_CC)" -C $(@D) $(PORTMAP_FLAGS)
 endef