Marvell phy: add functions to suspend and resume both interfaces: fiber and copper links.

These functions used standards registers in a different page
for both interfaces: copper and fiber.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Charles-Antoine Couret <charles-antoine.couret@nexvision.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>