msm: mdss: hdmi: clear ddc line before starting hdcp

Clear DDC line if scrambling and Rx status polling is still
going on. Check for all scrambling and Rx status errors and
stop polling in error cases. This needs to be done before
new hdcp authentication session is started to avoid any
authentication failures because of ddc line being busy.

Change-Id: I90957410172ca206d435a5549d689ada222f84db
Signed-off-by: Ajay Singh Parmar <aparmar@codeaurora.org>