linux-phytec-ti

net: phy: Drop OF dependency for MDIO_BCM_UNIMAC

The driver builds fine even with CONFIG_OF=n since we now have stubs that are
provided.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>