smdk4412-common: camera: Hold for 25 msec between preview cycles on restart

If doing a preview restart with an active listener, give the 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: I19ade52e703424e2d25deba23e5784d6f7dee02f