Fix the inverse 2x2 transform scaling factor
Fix the inverse 2x2 transform scaling factor

Scale down the 2x2 inverse transform transfer gain by 2.

Change-Id: Ifdd2ed302c05d08be142bc2fdef276f176e38c3d

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