drm/msm/hdmi: Fix HDMI pink strip issue seen on 8x96

A 2 pixel wide pink strip was observed on the left end of some HDMI
monitors configured in a HDMI mode.

It turned out that we were missing out on configuring AVI infoframes, and
unlike APQ8064, the 8x96 HDMI H/W seems to be sensitive to that.

Add configuration of AVI infoframes. While at it, make sure that
hdmi_audio_update is only called when we've detected that the monitor
supports HDMI.

Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>