Camera: add ISO mode support

Change-Id: Ied2075f950269990d836fc768b2c6c36088d494f
camera: add power mode support

Based on commit 7036d66bec7697160ba1b2e255f1e7fae0c8c435 from CAF,
branch ics_chocolate.

Change-Id: I8a60668b18980fd5e6f9dd341db5a8a63deb99d0