arm64: dts: marvell: mcbin: enable the fourth network interface

This patch enables the fourth network interface on the Marvell
Macchiatobin. It is configured in the 2500Base-X PHY mode. The SFP cage
is also described.

Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>