Adjust gm costing so GLOBAL_ZERO is treated as regular zeromv
Adjust gm costing so GLOBAL_ZERO is treated as regular zeromv

Change-Id: I1b41146ae844c985566f5f9fdaeb5d4a4a5927b6

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