net: phy: aquantia: Use get_features for the PHYs abilities

Use the new PHY driver call to get the PHYs supported features.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
[hkallweit1@gmail.com: removed new config_init callback from patch]
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>