ARM: dts: msm: Add gpio standby entry to camera2

Add gpio pin config for camera standby during
sensor powerup for the msm8974 cdp, fluid,
liquid and mtp boards

Change-Id: I463dad82c21eebdff21e735bc52e1c2b67032a10
Signed-off-by: Shivaramraje Nimbalkar Joshi <nimbalkars@codeaurora.org>