net: phy: extract link partner advertisement reading
Move reading the link partner advertisement out of genphy_read_status()
into its own separate function. This will allow re-use of this code by
PHY drivers that are able to read the resolved status from the PHY.
Tested-by: tinywrkb <tinywrkb@gmail.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>