msm: rotator: sync point support

Add MSM_ROTATOR_IOCTL_BUFFER_SYNC ioctl interface.
Rotator will create a timeline for each session at START, wait for
input fence and create released fence in this ioctl call,
signal the timeline after rotation is done.

Change-Id: I3738f8287d804ccd94e0a16ac0afb8b41b299c75
Signed-off-by: Ken Zhang <kenz@codeaurora.org>
msm: rotator: non-blocking rotate

Send request to a work queue and return right away.
Work queue will go through the commit queue to do the
rotation. wait_for_finish can be set to true to make
rotation go back to blocking.

Change-Id: Ifc2e36bd24d9681d42105f4ccbb62a8777af2a6c
Signed-off-by: Ken Zhang <kenz@codeaurora.org>