ARM: dts: msm: Bug fixes in device tree node for Venus on msmsamarium

Adds the video driver name, clock source for GDSC, clocks and
regulators for Venus. Removes unnecessary VBIF programming entries
for OCMEM.

Change-Id: Iecf5efbd146fd640069b69c5cc16382692117063
Signed-off-by: Praneeth Paladugu <ppaladug@codeaurora.org>