ARM: dts: msm: enable DSI SSC feature for msm8953

Enable spread spectrum clocking for DSI PLL for msm8953 target.
This will help to avoid EMI issues of DSI PLL with other subsystems.

Change-Id: I0d5ba6a53f7b2720e964101cebf9fddb16843533
Signed-off-by: Padmanabhan Komanduru <pkomandu@codeaurora.org>