colibri_vf: fix ethernet by adding explicit phy node

colibri_vf: fix ethernet by adding explicit phy node

The implicit fallback mechanism for searching the whole MDIO bus for at
least one PHY has been gone with the following commit b882005a18de
("drivers/net/fec: phy_init: remove redundant logic"). This lead to the
Ethernet driver erroring out as follows:

Net:   Could not get PHY for FEC0: addr -19
eth-1: fec@400d1000
Colibri VFxx # dhcp
Could not get PHY for FEC0: addr -19
Could not get PHY for FEC0: addr -19
Could not get PHY for FEC0: addr -19
Could not get PHY for FEC0: addr -19
No ethernet found.
Could not get PHY for FEC0: addr -19
Colibri VFxx #

This commit adds an explicit PHY node which makes it work again.

Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Reviewed-by: Hannes Schmelzer <hannes.schmelzer@br-automation.com>
Reviewed-by: Igor Opaniuk <igor.opaniuk@toradex.com>