msm: vidc: Check clocks state before Venus AXI halt

Venus AXI registers need venus VBIF clock. Without clock,
the register access may cause unknown behavior. Hence
check the clock state before accessing the register.

CRs-Fixed: 772609
Change-Id: I86fe8e85e497d0534b63d4a8af22e2f0c3b84659
Signed-off-by: Praneeth Paladugu <ppaladug@codeaurora.org>