Remove check for identical neighboring mv field in WARPED_MOTION
Remove check for identical neighboring mv field in WARPED_MOTION

This will allow us decode motion mode without knowing motion vectors
in the neighborhood.
Improves the performance by 0.3% (1.1->1.4)

Change-Id: Ie18ee2b02b1d2f89615bc8fa423beb1f9bd9a678

GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,smarter/aom,smarter/aom,smarter/aom,GrokImageCompression/aom,GrokImageCompression/aom,smarter/aom,smarter/aom,smarter/aom