ARM32/64 NEON versions of ScaleAddRows_NEON are implemented.

BUG=319
TESTED=libyuvTest.Scale* on ARM32/64 with Android
R=fbarchard@google.com

Change-Id: I45b88c2b5f576042ba5b3d8d6f8851257fdb7218

Review URL: https://webrtc-codereview.appspot.com/46379004

git-svn-id: http://libyuv.googlecode.com/svn/trunk@1326 16f28f9a-4ce2-e073-06de-1de4eb20be90