Make subpel_avg_variance unit-test's input aligned
Make subpel_avg_variance unit-test's input aligned

Make test input aligned, then jnt_comp's subpel_avg_variance simd
implementations pass unit tests.

Change-Id: Ic85442f3252ba4e8707e35fbd6344fd662aafd74

GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom