msm: mdss: hdmi: reset hdmi max supported TMDS clock

In current HDMI driver, SVDs and DTDs derived from EDID
of a DS HDMI sink are checked for supportness based
on previous connection's max TMDS clock.
Always reset the max TMDS clock supported by source
before reading EDID from DS HDMI device.

Change-Id: If5f58562f186634b1ed066fdebfc9fa6b55c6e8a
Signed-off-by: Narender Ankam <nankam@codeaurora.org>