msm: vidc: Remove legacy code for re-asserting Venus clocks

It's a workaround for a hardware bug on a platform that's already
EOLed.  No need to carry it for future releases.

Change-Id: I890d8001dffade410e72549da93f4eec56cbe433
Signed-off-by: Deva Ramasubramanian <dramasub@codeaurora.org>