sdm: Parse UBWC feature from MDP caps

1. Parse "ubwc" string in MDP caps feature list.
2. Add support to read system prop "sdm.debug.rotator_disable_ubwc".

Change-Id: Ie43b81237960e6c1e8784801b10cd39df069cddc
diff --git a/sdm/include/utils/debug.h b/sdm/include/utils/debug.h
index a5a10cd..0bd0429 100644
--- a/sdm/include/utils/debug.h
+++ b/sdm/include/utils/debug.h
@@ -68,6 +68,7 @@
   static bool IsPartialUpdateEnabled();
   static int GetMaxPipesPerMixer(DisplayType display_type);
   static bool IsVideoModeEnabled();
+  static bool IsRotatorUbwcDisabled();
 
  private:
   Debug();