adds TW_ADDITIONAL_RES to TW_RES

make it easier to add aditional resource files not just complete new theme

Change-Id: I6daca75929da03031812e66f25455e189b37a780
Signed-off-by: Xuefer <xuefer@gmail.com>
diff --git a/gui/Android.mk b/gui/Android.mk
index 03b796e..045824d 100644
--- a/gui/Android.mk
+++ b/gui/Android.mk
@@ -157,6 +157,7 @@
 else
     TWRP_THEME_LOC := $(TW_CUSTOM_THEME)
 endif
+TWRP_RES += $(TW_ADDITIONAL_RES)
 
 TWRP_RES_GEN := $(intermediates)/twrp
 ifneq ($(TW_USE_TOOLBOX), true)