Consistent names for inter mode probabilities and encodings.

Renaming vp9_sb_mv_ref_tree to vp9_inter_mode_tree, and
vp9_sb_mv_ref_encoding_array to vp9_inter_mode_encodings.

Change-Id: I0e91fbf81350d3ec5a2599064c74089b5d06133a
5 files changed