msm: mdss: check for audio support before notifying frameworks

In the current implementation DBA driver always assumes
the TV connected is supporting audio. However if the TV
connected is in DVI mode or it's EDID does not contain
any audio block then it will not support audio data.
Hence after parsing EDID, check if the connected TV has
support for audio and accordingly configure and send HPD
events to audio framework.

Change-Id: Id1d175b9c0c1c07bcb4447eeaa907a17c15df098
Signed-off-by: Sandeep Panda <spanda@codeaurora.org>
Signed-off-by: Vishnuvardhan Prodduturi <vproddut@codeaurora.org>