Renaming reference mode context calculation function.

Renames:
  vp9_get_pred_context_comp_inter_inter => vp9_get_reference_mode_context
  vp9_get_pred_prob_comp_inter_inter    => vp9_get_reference_mode_prob

Change-Id: I3bbb69481e6b0c848028667c9269f567f293d3bd
6 files changed