Making the forward transform consistent with high bit depth
Making the forward transform consistent with high bit depth

This patch changes the code for 16bit buffers to use the same
optimisation as is used for 8bit buffers. (See change-Id:
I0452da1786d59bc8bcbe0a35fdae9f623d1d44e1 for more information
about the optimisation)

Change-Id: I5f327a13a7b01fc356114a2aa9d1261bf76d8d69

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