The mv88e6390 MDIO bus controllers can support for clause 45 accesses.
The internal SERDES interfaces need this, and it is likely external
10GHz PHYs will be clause 45.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>