ARM: dts: msm: remove clk_src entries from sdm845 target

Clock enable and disable are no_op for core and vsync
clk source. Remove these two clock entries from sdm845
target for sde hardware.

Change-Id: Ia156387b1b3e6dc3a476f43b472f29780a88b8b4
Signed-off-by: Dhaval Patel <pdhaval@codeaurora.org>