Add support for devices that have an upside-down mounted display.

ZTE Blade is an example of this type of devices.
The original patch comes from Sebastian404 -> http://goo.gl/QC37W

Change-Id: Idffd97adf7da8a352617342bb6ff2161e6eac3a5
diff --git a/minui/Android.mk b/minui/Android.mk
index d71cea2..44f9fa1 100644
--- a/minui/Android.mk
+++ b/minui/Android.mk
@@ -15,6 +15,10 @@
     LOCAL_CFLAGS += -DBOARD_HAS_JANKY_BACKBUFFER
 endif
 
+ifeq ($(BOARD_HAS_FLIPPED_SCREEN), true)
+    LOCAL_CFLAGS += -DBOARD_HAS_FLIPPED_SCREEN
+endif
+
 LOCAL_MODULE := libminui
 
 include $(BUILD_STATIC_LIBRARY)