net: dsa: b53: spi: add missing MODULE_DEVICE_TABLE

This patch adds missing MODULE_DEVICE_TABLE definition which generates
correct modalias for automatic loading of this driver when it is built
as an external module.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/b53/b53_spi.c

@@ -335,6 +335,7 @@ static const struct of_device_id b53_spi_of_match[] = {
 	{ .compatible = "brcm,bcm53128" },
 	{ /* sentinel */ }
 };
+MODULE_DEVICE_TABLE(of, b53_spi_of_match);
 
 static struct spi_driver b53_spi_driver = {
 	.driver = {