anv: Do an end-of-pipe sync before updating AUX table entries

anv: Do an end-of-pipe sync before updating AUX table entries

We've found in GL that an actual end-of-pipe sync is required before
invalidating the aux tables and that a simple CS stall is insufficient.
If we're about to modify the actual AUX table entries from the GPU, we
should definitely make sure it's stopped dead before we do so.

Cc: mesa-stable@lists.freedesktop.org
Reviewed-by: Rafael Antognolli <rafael.antognolli@intel.com>
Tested-by: Marge Bot <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4206>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4206>