Use /twres instead of /res for theme resources

AOSP and other ROM trees now do a rm -rf of the res folder during
the ramdisk creation process that removes the TWRP resources.
Using /twres instead of /res works around this issue making TWRP
more compatible with AOSP and other build trees.

Change-Id: I0d4c7e06ca381ac5aa0069b6f2b8c47f7dec49e7
diff --git a/minuitwrp/Android.mk b/minuitwrp/Android.mk
index c4380aa..cff5321 100644
--- a/minuitwrp/Android.mk
+++ b/minuitwrp/Android.mk
@@ -123,6 +123,7 @@
     LOCAL_SRC_FILES += truetype.c
 endif
 
+LOCAL_CFLAGS += -DTWRES=\"$(TWRES_PATH)\"
 LOCAL_SHARED_LIBRARIES += libz libc libcutils libjpeg libpng
 LOCAL_STATIC_LIBRARIES += libpixelflinger_static
 LOCAL_MODULE_TAGS := eng