ARM: dts: msm: Add GDSC, GCC and CPU nodes for MSM8937

Add GCC and CPU clock controller device tree nodes to
support GCC and CPU clocks. Also add device tree nodes
for GDSCs.

Change-Id: I854032cfcf6a3d09836088a53d6457957e2f520b
Signed-off-by: Shefali Jain <shefjain@codeaurora.org>