arm64: dts: marvell: mcbin: add comphy references to Ethernet ports

This patch adds comphy phandles to the Ethernet ports in the mcbin
device tree. The comphy is used to configure the serdes PHYs used by
these ports.

Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>