drm/msm/dp: Add Display Port HPD feature

Configure HPD registers in DP controller and
enable HPD interrupt.

Add interrupt to handle HPD connect and disconnect events.

Changes in v8: None

Signed-off-by: Tanmay Shah <tanmay@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>
7 files changed