net: add extended function to phy API

Some phys (Micrel) has extended registers that must be
accessed in a special way. Add pointers to the phy driver
structure to allow to use these functions with mdio command.

Signed-off-by: Stefano Babic <sbabic@denx.de>

include/phy.h

@@ -125,6 +125,9 @@ struct phy_driver {
 	/* Called when bringing down the controller */
 	int (*shutdown)(struct phy_device *phydev);
 
+	int (*readext)(struct phy_device *phydev, int addr, int devad, int reg);
+	int (*writeext)(struct phy_device *phydev, int addr, int devad, int reg,
+			u16 val);
 	struct list_head list;
 };