Fix up old libminui to compile

Implement some needed updates to libminui to make it compile for
healthd. Note that res_create_multi_display_surface is not fully
implemented so healthd may still have issues with displaying some
graphics. Will update later when we are able to test these changes.

Change-Id: Ic1095a998f5dfe7e36a08384c86da28e0524a03f
diff --git a/minui/graphics.c b/minui/graphics.c
index 8f95175..948a07c 100644
--- a/minui/graphics.c
+++ b/minui/graphics.c
@@ -495,3 +495,11 @@
 {
     get_memory_surface( (GGLSurface*) surface);
 }
+
+// These are new graphics functions from 5.0 that were not available in
+// 4.4 that are required by charger and healthd
+void gr_clear()
+{
+	return;
+}
+