overlay: Map NV12 encodeable to venus format

The NV12 encodeable format is set for wifi displays but isn't
mapped to any MDP format. On B-Family targets the format is
equivalent to the venus yuv format.

Change-Id: I75e20c079e4b2e21decc39c29d9ed25953276df9
diff --git a/liboverlay/overlayUtils.cpp b/liboverlay/overlayUtils.cpp
index c3d00f1..927e7e9 100644
--- a/liboverlay/overlayUtils.cpp
+++ b/liboverlay/overlayUtils.cpp
@@ -119,6 +119,9 @@
         case HAL_PIXEL_FORMAT_YCrCb_444_SP:
             return MDP_Y_CRCB_H1V1;
         case HAL_PIXEL_FORMAT_YCbCr_420_SP_VENUS:
+        case HAL_PIXEL_FORMAT_NV12_ENCODEABLE:
+            //NV12 encodeable format maps to the venus format on
+            //B-Family targets
             return MDP_Y_CBCR_H2V2_VENUS;
         default:
             //Unsupported by MDP