SEL_CLK is only used on the primary ramdac.

OF says LCD for DFP as well, we discriminate the caller of this function. -OF says LCD for DFP as well, we discriminate the caller of this function.

special case of nv_read_tmds to find crtc associated with an output. this does not give a correct answer for off-chip dvi, but there s no use for such an answer anyway.