i2c: i2c-mux-pinctrl: use deferred probe when adapter not found

If it is not there yet, it might appear later.

Signed-off-by: Wolfram Sang <[e-mail]>

drivers/i2c/muxes/i2c-mux-pinctrl.c

···
 	adapter = of_find_i2c_adapter_by_node(adapter_np);
 	if (!adapter) {
 		dev_err(mux->dev, "Cannot find parent bus\n");
-		return -ENODEV;
+		return -EPROBE_DEFER;
 	}
 	mux->pdata->parent_bus_num = i2c_adapter_id(adapter);
 	put_device(&adapter->dev);
···
 	if (!mux->parent) {
 		dev_err(&pdev->dev, "Parent adapter (%d) not found\n",
 			mux->pdata->parent_bus_num);
-		ret = -ENODEV;
+		ret = -EPROBE_DEFER;
 		goto err;
 	}