ARM: dts: msm: Add SDAM ramp configuration for PWM channels on PMI632

Set SDAM based ramp configurations for the PWM channels that are used
for controlling RGB LEDs. The RGB LEDs can be configured to blink with
various ramping patterns.

Change-Id: I16c2709cedb6187901a87f6ff12342147cb5dc3f
Signed-off-by: Fenglin Wu <fenglinw@codeaurora.org>