drm/i915/gt: Poll aux invalidation register bit on invalidation

drm/i915/gt: Poll aux invalidation register bit on invalidation

For platforms that use Aux CCS, wait for aux invalidation to
complete by checking the aux invalidation register bit is
cleared.

Fixes: 972282c4cf24 ("drm/i915/gen12: Add aux table invalidate for all engines")
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>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230725001950.1014671-7-andi.shyti@linux.intel.com