To avoid using a UV_PREDICTION_MODE with intra_mode_to_tx_type_context,
a wrapper function is added. Using a UV_PREDICTION_MODE with
intra_mode_to_tx_type_context is problematic with UV_CFL_PRED which
needs to be converted to DC_PRED.

Change-Id: I68320e34dd5e616d0f15ca2c1c951440243968cf