fix live wallpapers on Droid

On omap3 h/w we force opaque formats to RGB_565 instead of RGBX_8888
because the GL driver doesn't support it. RGBX_8888 is always remapped
to RGBA_8888.

Change-Id: I0bfabeb98c8d3a399079e6797cf2a0ee95915324
diff --git a/libs/surfaceflinger/Android.mk b/libs/surfaceflinger/Android.mk
index dbe351e..a14bfb5 100644
--- a/libs/surfaceflinger/Android.mk
+++ b/libs/surfaceflinger/Android.mk
@@ -20,6 +20,10 @@
 LOCAL_CFLAGS:= -DLOG_TAG=\"SurfaceFlinger\"
 LOCAL_CFLAGS += -DGL_GLEXT_PROTOTYPES -DEGL_EGLEXT_PROTOTYPES
 
+ifeq ($(TARGET_BOARD_PLATFORM), omap3)
+	LOCAL_CFLAGS += -DNO_RGBX_8888
+endif
+
 # need "-lrt" on Linux simulator to pick up clock_gettime
 ifeq ($(TARGET_SIMULATOR),true)
 	ifeq ($(HOST_OS),linux)