msm: camera: Fix power related issues across sensor modules

Assign the power settings pointer to null after freeing it
and reset the power settings size variable to 0. Free power
settings if the sensor is in correct state. Add check in
acquire device to verify if the device has been probed
successfully before acquire.

Change-Id: I73f795fd0d8f0c3f17d49d2895c896bc6d349eea
Signed-off-by: Jigarkumar Zala <jzala@codeaurora.org>
Signed-off-by: Vishalsingh Hajeri <vhajeri@codeaurora.org>
Signed-off-by: Venkat Chinta <vchinta@codeaurora.org>