drm/i915/gt: Ensure memory quiesced before invalidation

All memory traffic must be quiesced before requesting
an aux invalidation on platforms that use Aux CCS.

Fixes: 972282c4 ("drm/i915/gen12: Add aux table invalidate for all engines")
Requires: a2a4aa0eef3b ("drm/i915: Add the gen12_needs_ccs_aux_inv helper")
Signed-off-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Cc: <stable@vger.kernel.org> # v5.8+
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230725001950.1014671-4-andi.shyti@linux.intel.com