ARM: dts: msm: Add camera DT for apq8009 robot som

apq8009-robot-som support two cameras,and it's hardware
design is different with mtp's,the gpios used by camera_1
conficts with mtp gpio key, add camera device tree node
based on H.W. design and disable gpio_key.

Change-Id: I8fec129c74182e3ef5543e78a6b833b6be6f9f36
Signed-off-by: Tao Jiang <taojiang@codeaurora.org>