Revert "display: Video Encoding not working"

* "display: Video Encoding not working" was mismerged
  into another commit (de13ed01a21db7d6b46962729fa3f9ff3ef8c2cd)
  by upstream in kk_2.7 from kk_3.5
* The original commit has since been reverted in kk_3.5,
  this is a cherry-pick of that.

This reverts commit 0a1db6aef28c3b90d1f992f56abc562dbae10b55.
Video encoder uses the NV12 encodeable format again.

Change-Id: I1b5170a5c2b5c7de0791cc5bc44457257519f749
hwc: bring back fb support for primary for mdp303.

Change-Id: I98cf0fdae6b9b1100c97ac319ab1c321f55fe507