ARM: dts: msm: update LPG/LED configuration in PM6150L

Add ramp configurations for the LPG channels so that the RGB LEDs
connecting to these channels can be controlled with blinking patterns.
Also add timer as the default trigger for RGB LEDs.

Change-Id: I4c16252880542ff9646d680c0fcdf5d023ce5620
Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>