ARM: dts: msm: Update the clock_dispcc node on SM6150

Update the DISPCC clock controller device node to register to
actual DISPCC driver. Also update the video GDSCs by replacing
the dummy nodes with actual GDSC device nodes.

Change-Id: If2c94befef0e132847c1688f98696dd6200d9980
Signed-off-by: Odelu Kukatla <okukatla@codeaurora.org>