msm: camera: Handle actuator close before power down

In case when userspace process is killed, actuator
subdev is first closed and then power down is called.
In this sequence, we need to handle actuator states
properly to shutdown all the regulators during close.

Change-Id: I843b463a1b576971e16d1554ded20984dd0ec436
Signed-off-by: Mounika Reddy Tangirala <mtangi@codeaurora.org>