drm: msm: sde: api support for blocking lut dma kick off

If lut dma is busy it will block the control flush and start on the sde
block. This can cause under-run in the sde block in video mode panels.
Enhance the api of lut dma kick-off to be configured as
blocking/non-blocking.

Change-Id: Ibb009978a9ea059b6ed3fa97ebb7588ecbdb10eb
Signed-off-by: Gopikrishnaiah Anandan <agopik@codeaurora.org>