drm/msm/sde: add autorefresh property to sde crtc

Add initial exposure of an autorefresh property, as well as a
basic check to prevent autorefresh and partial update feature
concurrency.

Change-Id: I3078c2b940ed90ed502e2aba9f688c58990fed87
Signed-off-by: Lloyd Atkinson <latkinso@codeaurora.org>