camera: don't disable autofocus based on zsl, use its own prop

Change-Id: I401bbe9347a1fbc3b839d7a1b17490d189785fa0
msm8960: camera: Only enable ZSL for photos

 * Don't turn on ZSL for camcorder unless you like pain.

Change-Id: I390843c3bbf6fff4caecd7477086e66eebe0205c