net: phy: realtek: add missing entry for RTL8211 to mdio_device_id table

When adding support for RTL8211 I forgot to update the mdio_device_id
table.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Fixes: d241d4aa ("net: phy: realtek: add support for RTL8211")
Signed-off-by: David S. Miller <davem@davemloft.net>