arm/dt: msm8974: autofocus support for sensor imx135

The autofocus actuator is having a powerdown pin which
needs to be pulled up for af operation. the CAM_STANDBY
pin is conencted to the AF power down. the corresponding
gpio is enabled

Change-Id: I8dcb553e51c129db84235e4dcfb81b630007612d
Signed-off-by: Jeyaprakash Soundrapandian <jsoundra@codeaurora.org>