Apply skip_ref_frame_mask to all sub blocks
Apply skip_ref_frame_mask to all sub blocks

Currently skip_ref_frame_mask only applied to rect
blocks, this CL apply it to all sub blocks including
square blocks in PARTITION_HORZ_A/B and
PARTITION_VERT_A/B.

For encoder, about 0.6% faster shows by encoding
20 frame of BasketballDrill_832x480_50.y4m at 800kbps
on speed 1. The coding performance is about 0.01% loss
on average.

STATS_CHANGED expected

Change-Id: I097245bbc2f954c5a2a4b60c4ea05af8581c1a82

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