net: phy: fix aneg restart in phy_ethtool_set_eee

phy_restart_aneg() enables aneg in the PHY. That's not what we want
if phydev->autoneg is disabled. In this case still update EEE
advertisement register, but don't enable aneg and don't trigger an
aneg restart.

Fixes: f75abeb8 ("net: phy: restart phy autonegotiation after EEE advertisment change")
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>