msm: vidc: enable passive buses while unload firmware

In msm8937, MM NOC default voting from SMMU driver side has been removed.
It is individual client responsibility to vote for bus while
firmware load & unloading.
Enable passive buses while firmware unloading.

Change-Id: Ic16f924ecf8578bddb9a0c727f8fee4c1a62e5ef
CRs-Fixed: 1013490
Signed-off-by: Srinu Gorle <sgorle@codeaurora.org>