msm: camera: icp: Reduce the device idle timer

Reduce the device idle timer to 400 msecs, to turn off clocks that
are not in use and save power.

Change-Id: I3c76c645bf11a05cdc7a8cc125719b00c198c87b
Signed-off-by: Lynus Vaz <lvaz@codeaurora.org>
Signed-off-by: Tony Lijo Jose <tjose@codeaurora.org>