According to the datasheet the mt7620n have a fixed switch configuration
with 5 ephy (10/100) port. No RGMII configuration is possible.
Drop the mdio node as well. Without RGMII, the mdio node doesn't make any
sense
Signed-off-by: Giuseppe Lippolis <giu.lippolis@gmail.com>
[drop mdio node, enable port4 by default]
Signed-off-by: Mathias Kresin <dev@kresin.me>