ARM: dts: msm: Add support for AUO 390p cmd mode panel on msm8909w

Add changes to:
1.add panel init sequence, on/off commandsand other panel properties
for AUO 390p cmd mode panel
2.configure PMIC gpio 12 as a fixed regulator and add it as panel
power supply
3.support for BACKLIGHT_EN gpio.

Change-Id: Ic3772ba83f8e072d2e716fa92b18aa027458a545
Signed-off-by: Rashi Bindra <rbindra@codeaurora.org>