net: phy: aquantia: use macro PHY_ID_MATCH_MODEL

Make use of macro PHY_ID_MATCH_MODEL to simplify the code.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>