ARM: dts: msm: update reference to msm8937 dsi pll clocks

Latest DSI 28nm HPM PHY driver has support for two
independent DSI PLL. Update the reference to DSI PLL clocks
in msm8937 device tree based on latest DSI PHY driver.

Change-Id: I11d2774124ecb2d0743b098db2ce3a01be71440b
Signed-off-by: Sandeep Panda <spanda@codeaurora.org>