drm/msm/dp: add support to configure sink in power saving mode

Add support to send the PSM AUX command to the sink whenever
required during the Display Port power down sequence.

Change-Id: I7f3d3248de73c7c847a2c0915ba6732b426a5854
Signed-off-by: Padmanabhan Komanduru <pkomandu@codeaurora.org>
7 files changed