ARM: dts: msm: Add video clocks on SDM670

For a SDM670 SKU, one video core is disabled. The
memory associated with the disable core remains
ON as the associated clock keeps it ON.
Add the clocks and related configs in order to
set the clock flags. Setting the desired flag for
the associated clocks would disable the mem_core.

Change-Id: Iae3c6850a8867bf58c5ab2501a598329aa6a758e
Signed-off-by: Vikash Garodia <vgarodia@codeaurora.org>