msm/sde/rotator: add support to check if done handler is scheduled

In some cases, stop streaming request can come while
the commit is going on. Add support to check if
done handler is scheduled and if it is not scheduled,
wait again so that commit can be completed before
proceeding with the stop streaming request.

Change-Id: Iae7c04d69c340f9ce02fa4172e581900691e6b1a
Signed-off-by: Krishna Manikandan <mkrishn@codeaurora.org>