phy: marvell: Add support for 88E3016 FastEthernet PHY

Marvell 88E3016 is a FastEthernet PHY that also can be found in Marvell
Berlin SoCs as integrated PHY.

Tested-by: Antoine Ténart <antoine.tenart@free-electrons.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>