drm/xe/vf: Don't touch GuC irq registers if using memory irqs

On platforms where VFs are using memory based interrupts, we
missed invalid access to no longer existing interrupt registers,
as we keep them marked with XE_REG_OPTION_VF. To fix that just
either setup memirq vectors in GuC or enable legacy interrupts.

Fixes: aef4eb7c ("drm/xe/vf: Setup memory based interrupts in GuC")
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240617154736.685-1-michal.wajdeczko@intel.com

drivers/gpu/drm/xe/xe_guc.c

@@ -854,8 +854,6 @@ int xe_guc_enable_communication(struct xe_guc *guc)
 	struct xe_device *xe = guc_to_xe(guc);
 	int err;
 
-	guc_enable_irq(guc);
-
 	if (IS_SRIOV_VF(xe) && xe_device_has_memirq(xe)) {
 		struct xe_gt *gt = guc_to_gt(guc);
 		struct xe_tile *tile = gt_to_tile(gt);
@@ -863,6 +861,8 @@ int xe_guc_enable_communication(struct xe_guc *guc)
 		err = xe_memirq_init_guc(&tile->sriov.vf.memirq, guc);
 		if (err)
 			return err;
+	} else {
+		guc_enable_irq(guc);
 	}
 
 	xe_mmio_rmw32(guc_to_gt(guc), PMINTRMSK,