Let is_interp_needed always return 1
Let is_interp_needed always return 1

This CL will cause
0.122% PSNR drop on lowres dataset
0.059% PSNR drop on midres dataset

However, it will facilitate hardware implementation.

Change-Id: I0a0713acacbfd571509a721337711c021915dd3c

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