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