Some MAC hardware cannot support a subset of link modes. e.g. often
1Gbps Full duplex is supported, but Half duplex is not. Add a helper
to remove such a link mode.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>