net: phy: add missing SPEED_14000

Fixes: 0d7e2d21 ("IB/ipoib: add get_link_ksettings in ethtool")
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>