ARM: dts: msm: Add graphic clock support for SDM845 v2

Add the clock nodes for GPUCC and GFX clocks on SDM845 v2
device.

CRs-Fixed: 2088018
Change-Id: I14cab27a04a01b6b8b839ee6b1379c240f88779b
Signed-off-by: Vicky Wallace <vwallace@codeaurora.org>