drm/i915/mtl: Add missing steering table terminators

The termination entries were missing for a couple of the recently-added
MTL steering tables.

Fixes: f32898c9 ("drm/i915/xelpg: Add multicast steering")
Fixes: a7ec65fc ("drm/i915/xelpmp: Add multicast steering for media GT")
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221028224022.964997-1-matthew.d.roper@intel.com

drivers/gpu/drm/i915/gt/intel_gt_mcr.c

@@ -128,11 +128,13 @@ static const struct intel_mmio_range xelpg_dss_steering_table[] = {
 	{ 0x00D800, 0x00D87F },		/* SLICE */
 	{ 0x00DC00, 0x00DCFF },		/* SLICE */
 	{ 0x00DE80, 0x00E8FF },		/* DSS (0xE000-0xE0FF reserved) */
+	{},
 };
 
 static const struct intel_mmio_range xelpmp_oaddrm_steering_table[] = {
 	{ 0x393200, 0x39323F },
 	{ 0x393400, 0x3934FF },
+	{},
 };
 
 void intel_gt_mcr_init(struct intel_gt *gt)