anv: Enable blitter engine unconditionally on ACM+
What does this MR do and why?
I did test the blitter engine locally on ACM platform with the older GuC version 70.5.1,
we didn't hit the issues that we were hitting with the compute queue.
CI system has the latest GuC firmware version and it also came back clean
(http://mesa-ci-results.jf.intel.com/custom/builds/460/group/63a9f0ea7bb98050796b649e85481845) except
for one failure, don't think it's related to the copy queue.