smdk4412-common: camera: implement CAMERA_MSG_FOCUS_MOVE to report CAF

Since we are querying the status of CAF in real time, implement
CAMERA_MSG_FOCUS_MOVE to report the CAF status.

Also monitor the state of AutoFocus and report success or failure
only when AutoFocus has started. This prevents reporting false
AutoFocus status which relates to the previous AutoFocus result.

Change-Id: Icb151dca150f932b42b276c45ec392e3dae413cc
camera: Hold 25 msec between preview cycles on restart

If doing a preview restart with an active listener, give said
listener a bit of time to clean up before starting up the preview
again. This should be sufficient to prevent shutdown/start race
conditions during externally triggered restarts.

Change-Id: Id4a722c472eeffb50a332b0dabc29d9e23062883