drm/edid: Make max_tmds_clock kHz instead of MHz

drm/edid: Make max_tmds_clock kHz instead of MHz

We generally store clocks in kHz, so let's do that for the
HDMI max TMDS clock value as well. Less surpising.

v2: Deal with superfluous code shuffling

Cc: Alex Deucher <[email protected]>
Cc: "Christian König" <[email protected]>
Signed-off-by: Ville Syrjälä <[email protected]>
Reviewed-by: Christian König <[email protected]> (v1)
Reviewed-by: Alex Deucher <[email protected]>
Signed-off-by: Daniel Vetter <[email protected]>
Link: http://patchwork.freedesktop.org/patch/msgid/[email protected]