net: phy: add Marvell Alaska X 88X3310 10Gigabit PHY support

Add phylib support for the Marvell Alaska X 10 Gigabit PHY (MV88X3310).
This phy is able to operate at 10G, 1G, 100M and 10M speeds, and only
supports Clause 45 accesses.

The PHY appears (based on the vendor IDs) to be two different vendors
IP, with each devad containing several instances.

This PHY driver has only been tested with the RJ45 copper port, fiber
port and a Marvell Armada 8040-based ethernet interface.

It should be noted that to use the full range of speeds, MAC drivers
need to also reconfigure the link mode as per phydev->interface, since
the PHY automatically changes its interface mode depending on the
negotiated speed.

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>