drm/msm/dp: avoid audio reconfig delays

During link maintenance, disable audio first and then proceed
further. Once the maintenance is completed, re-enable the audio.
Currently audio disable/enable is done after link maintenance
which introduces delays for next sink request. Avoid audio delays
to fix DisplayPort CTS issues.

CRs-Fixed: 2146479
Change-Id: Icb881552842e711e7660a96c64f00a6d1312a47c
Signed-off-by: Ajay Singh Parmar <aparmar@codeaurora.org>
Signed-off-by: Steve Cohen <cohens@codeaurora.org>