camera: Always enable preview metadata

 * Remove the ifdefs which enable/disable the preview metadata during
   start/stop preview.  This causes issues with face detection and
   other uses on new hardware.
 * I am not aware of any hardware which still needs this.

Change-Id: I3dd0941a61affb4862a2e8f4f0c2cf59c95b150e
camera: Include camera parameters in device tree

Simple option to include camera parameters into your device tree.
All info can be seen here:
http://forum.xda-developers.com/android/help/dev-mod-to-add-extra-camera-parameters-t2814578

Change-Id: Ic5b27670fd0bb6ec11f6e902ce7ec3ca2ca10827