ARM: dts: msm: fix MPP configuration used for Liquid msm8994

The selected MPP function used to control the
PWM backlight is not correct. This causes the backlight
not to come up properly. Fix this issue by configuring
the proper function selection for MPP 1.

Change-Id: I546b821e28c48926b35c46166e8a37b7346aaf82
Signed-off-by: Chandan Uddaraju <chandanu@codeaurora.org>