Fix the top-right reference block location
Fix the top-right reference block location

This commit fixes the top-right reference block location for block
sizes above 8x8. It improves the coding performance of ref-mv:

lowres 0.08%
midres 0.15%

Thanks to jiafeng@ for finding this issue.

Change-Id: I70750fc7b18bf0126d3e07abc1b63ca5a160193e

mbebenita/aom,GrokImageCompression/aom,mbebenita/aom,smarter/aom,smarter/aom,luctrudeau/aom,luctrudeau/aom,GrokImageCompression/aom,mbebenita/aom,luctrudeau/aom,smarter/aom,mbebenita/aom,smarter/aom,mbebenita/aom,GrokImageCompression/aom,luctrudeau/aom,mbebenita/aom,luctrudeau/aom,smarter/aom,GrokImageCompression/aom,GrokImageCompression/aom,luctrudeau/aom,mbebenita/aom,mbebenita/aom,GrokImageCompression/aom,mbebenita/aom,smarter/aom