ARM: dts: msm: config disp gpios for samarium mtp

Configure the DSI panel reset, display enable
and backlight GPIOs for SAMARIUM MTP device tree.
These GPIOs are necessary for DSI panel to function
on MTP board.

Change-Id: Id6d6c1b64be5841e025fbc368825521eb6b04f7a
Signed-off-by: Manoj Rao <manojraj@codeaurora.org>