Fix get_entropy_contexts_plane for 2x2 transform block size
Fix get_entropy_contexts_plane for 2x2 transform block size

Change-Id: I094d7787b5ababa4855a0c57064c09c6fa02aede

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