There is a race condition where the PHY state machine can change
members of the phydev structure at the same time userspace requests a
change via ethtool. To prevent this, have phy_ethtool_ksettings_set
take the PHY lock.

Fixes: 2d55173e ("phy: add generic function to support ksetting support")
Reported-by: NWalter Stoll <Walter.Stoll@duagon.com>
Suggested-by: NWalter Stoll <Walter.Stoll@duagon.com>
Tested-by: NWalter Stoll <Walter.Stoll@duagon.com>
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>