msm: vidc: Halt the AXI after SYS error from Venus

When SYS_ERROR recieved from Venus, HW may be accessing input
and\or output buffers. As part of clean-up driver un-maps the
buffers that are still being used HW. This may cause page faults.
Hence driver needs to halt the AXI to make sure all the pending
transactions are cleared and future transactions are blocked.

Change-Id: I3d0be5b3d0b339dabccbad05f3d42b78ebd89944
Signed-off-by: Praneeth Paladugu <ppaladug@codeaurora.org>