net: phy: ensure that genphy_c45_an_config_eee_aneg() sees new value of phydev->eee_cfg.eee_enabled

This is a follow-up to 41ffcd95 ("net: phy: fix phylib's dual
eee_enabled") and resolves an issue with genphy_c45_an_config_eee_aneg()
(called from genphy_c45_ethtool_set_eee) not seeing the new value of
phydev->eee_cfg.eee_enabled.

Fixes: 49168d19 ("net: phy: Add phy_support_eee() indicating MAC support EEE")
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reported-by: Choong Yong Liang <yong.liang.choong@linux.intel.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>