drm/nv50/disp: allow PCI_US pushbuf binding

drivers/gpu/drm/nouveau/core/engine/disp/nv50.c

@@ -141,6 +141,9 @@ nv50_disp_dmac_create_(struct nouveau_object *parent,
 		case NV_MEM_TARGET_VRAM:
 			dmac->push = 0x00000000 | dmac->pushdma->start >> 8;
 			break;
+		case NV_MEM_TARGET_PCI_NOSNOOP:
+			dmac->push = 0x00000003 | dmac->pushdma->start >> 8;
+			break;
 		default:
 			return -EINVAL;
 		}