drm/i915: Add the gen12_needs_ccs_aux_inv helper

drm/i915: Add the gen12_needs_ccs_aux_inv helper

We always assumed that a device might either have AUX or FLAT
CCS, but this is an approximation that is not always true, e.g.
PVC represents an exception.

Set the basis for future finer selection by implementing a
boolean gen12_needs_ccs_aux_inv() function that tells whether aux
invalidation is needed or not.

Currently PVC is the only exception to the above mentioned rule.

Requires: 059ae7ae2a1c ("drm/i915/gt: Cleanup aux invalidation registers")
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Jonathan Cavitt <jonathan.cavitt@intel.com>
Cc: <stable@vger.kernel.org> # v5.8+
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230725001950.1014671-3-andi.shyti@linux.intel.com