net: phy: fix marvell phy status reading

The Marvell driver incorrectly provides phydev->lp_advertising as the
logical and of the link partner's advert and our advert.  This is
incorrect - this field is supposed to store the link parter's unmodified
advertisment.

This allows ethtool to report the correct link partner auto-negotiation
status.

Fixes: be937f1f ("Marvell PHY m88e1111 driver fix")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>