drm/xe: fix has_llc on rkl

Matches i915. Assumption going forward is that non-llc + igpu is only a
thing on MTL+ which should have explicit coherency pat_index settings
for COH_NONE, 1WAY and 2WAY.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Pallavi Mishra <pallavi.mishra@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Pallavi Mishra <pallavi.mishra@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

drivers/gpu/drm/xe/xe_pci.c

@@ -232,6 +232,7 @@ static const struct xe_device_desc rkl_desc = {
 	.graphics = &graphics_xelp,
 	.media = &media_xem,
 	PLATFORM(XE_ROCKETLAKE),
+	.has_llc = true,
 	.require_force_probe = true,
 };