msm: mdss: hdmi: set tmds clock ratio bit if scdc is supported

Set TMDS_BIT_CLOCK_RATIO bit in the SCDC port based on the bit rate
for the current mode. This bit has to be set before the TMDS clock is
turned on.

Change-Id: I315e00a032a1465974431e09ed2918ff353cb6de
Signed-off-by: Vinu Deokaran <vinud@codeaurora.org>
Signed-off-by: Casey Piper <cpiper@codeaurora.org>