hwc: Add support for Macro Tile feature

Macro tile is enabled only if all the conditions are met:
  1. GPU hardware should support Macro Tiling.
  2. MDSS hardware should support Macro Tiling.
  3. USAGE flags shouldnt contain GRALLOC_USAGE_SW_READ_OFTEN and
     GRALLOC_USAGE_SW_WRITE_OFTEN.
  4. RGB 16bit and 32bit formats.
  5. persist.hwc.macro_tile_enable flag should be enabled.

PRIV_FLAGS_TILE_RENDERED flag is added to indicate whether the layer
is rendered/composited in Macro Tiling or Linear format.

Change-Id: Ie3139839c84d76c5d1a2300f33910a09eb7336f4
diff --git a/libhwcomposer/hwc_fbupdate.h b/libhwcomposer/hwc_fbupdate.h
index 355e429..4b449c8 100644
--- a/libhwcomposer/hwc_fbupdate.h
+++ b/libhwcomposer/hwc_fbupdate.h
@@ -53,6 +53,7 @@
     overlay::Rotator *mRot;
     int mAlignedFBWidth;
     int mAlignedFBHeight;
+    int mTileEnabled;
 };
 
 //Non-Split panel handler.