net: ethernet: marvell: mvneta: use new api ethtool_{get|set}_link_ksettings

The ethtool api {get|set}_settings is deprecated.
We move the mvneta driver to new api {get|set}_link_ksettings.

We use the generic function phy_ethtool_get_link_ksettings,
and update old mvneta_ethtool_set_settings to the new api.

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