Properly pass compiler flags detected at configure-time

Index: Drivers/Screen/AtSpi2/Makefile.in
--- Drivers/Screen/AtSpi2/Makefile.in.orig
+++ Drivers/Screen/AtSpi2/Makefile.in
@@ -32,7 +32,7 @@ screen.$O: $(OBJ_FILES)
 	$(MKREL) $@ $(OBJ_FILES)
 
 xsel.$O: $(SRC_TOP)$(PGM_DIR)/xsel.c
-	$(CC) $(SCR_CFLAGS) -c $<
+	$(CC) $(SCR_CFLAGS) $(X11_INCLUDES) -c $<
 
 a2_screen.$O:
 	$(CC) $(SCR_CFLAGS) $(ATSPI2_INCLUDES) $(DBUS_INCLUDES) $(GLIB2_INCLUDES) -c $(SRC_DIR)/a2_screen.c
