ARM: dts: msm: enable DSI SSC feature for msm8937

Enable spread spectrum clocking for DSI PLL for msm8937 target.
This will help to avoid EMI issues of DSI PLL with other subsystems.

Change-Id: I3e1e746e611c8f42136d4015f026978edd40cf77
Signed-off-by: Padmanabhan Komanduru <pkomandu@codeaurora.org>