Revert "net: ethernet: bcmgenet: use new api ethtool_{get|set}_link_ksettings"

This reverts commit 6b352ebc ("net: ethernet: broadcom: bcmgenet:
use new api ethtool_{get|set}_link_ksettings").

We needs to revert the commit 62469c76 ("net: ethernet: bcmgenet:
use phydev from struct net_device"), because this commit add a
regression. As the commit 6b352ebc

 ("net: ethernet: broadcom:
bcmgenet: use new api ethtool_{get|set}_link_ksettings") depend
on the first one, we also need to revert it first.

Signed-off-by: Philippe Reynes <tremyfr@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>