drm/xe: Lock GGTT on when restoring kernel BOs

Make lockdep happy as we required to hold the GGTT when calling
xe_ggtt_map_bo.
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>

drivers/gpu/drm/xe/xe_bo_evict.c

@@ -147,8 +147,11 @@ int xe_bo_restore_kernel(struct xe_device *xe)
 			return ret;
 		}
 
-		if (bo->flags & XE_BO_CREATE_GGTT_BIT)
+		if (bo->flags & XE_BO_CREATE_GGTT_BIT) {
+			mutex_lock(&bo->gt->mem.ggtt->lock);
 			xe_ggtt_map_bo(bo->gt->mem.ggtt, bo);
+			mutex_unlock(&bo->gt->mem.ggtt->lock);
+		}
 
 		/*
 		 * We expect validate to trigger a move VRAM and our move code