It appears that CP can over-fetch push constants slightly.  While it
otherwise has no problem fetching from an alignment of 32 bytes, if that
32 bytes is at the end of a mapped bo, this can trigger fetching up to
32 bytes beyond the patch, triggering an iova fault.  While otherwise
"harmless", it is probably better to not have random intermittent
faults.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Part-of: <!11142>