Refactor tx_size to pixel number mapping in reconintra.c
Refactor tx_size to pixel number mapping in reconintra.c

Change-Id: Id66a14a869df8317c5bbb693d14262326fe84206

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