mdio: Move mdiobus_read/write operatings into mdio.h

These are logically MDIO operations, not phy operations, so move them
into the mdio header.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/mdio.h b/include/linux/mdio.h
index b42963b..0d073c2 100644
--- a/include/linux/mdio.h
+++ b/include/linux/mdio.h
@@ -11,6 +11,7 @@
 
 #include <uapi/linux/mdio.h>
 
+struct mii_bus;
 
 static inline bool mdio_phy_id_is_c45(int phy_id)
 {
@@ -173,4 +174,9 @@
 	return reg;
 }
 
+int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum);
+int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum);
+int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val);
+int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val);
+
 #endif /* __LINUX_MDIO_H__ */