msm: display: qpic: Add pinctrl support in qpic

Add pinctrl support for the installation of the required GPIOs
from devicetree, and make appropriate changes in the driver to
initialize and set the pins to active and sleep states during
panel on and off stages respectively in QPIC driver.

Change-Id: I7e227843553c2a32cdd8eed3c622af7e3d556e6c
Signed-off-by: Zohaib Alam <zalam@codeaurora.org>
Signed-off-by: anisha agarwal <anishaa@codeaurora.org>