ARM: dts: msm: gpios for DSI ctrlr on samarium CDP

Define all the gpios needed for DSI controller to
enable the panel. The GPIOs are required for display
power, DSI reset and backlight power enable.

Change-Id: Id2bcbaf4cbf975406d967c0c915f49f4c2fee470
Signed-off-by: Manoj Rao <manojraj@codeaurora.org>