of: mdio: remove the 'extern' keyword from function declarations

The 'extern' keyword in headers doesn't have any benefit. Remove them
all from the of_mdio.h header.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/of_mdio.h

@@ -12,26 +12,25 @@
 #include <linux/of.h>
 
 #if IS_ENABLED(CONFIG_OF_MDIO)
-extern bool of_mdiobus_child_is_phy(struct device_node *child);
-extern int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np);
-extern struct phy_device *of_phy_find_device(struct device_node *phy_np);
-extern struct phy_device *of_phy_connect(struct net_device *dev,
-					 struct device_node *phy_np,
-					 void (*hndlr)(struct net_device *),
-					 u32 flags, phy_interface_t iface);
-extern struct phy_device *
+bool of_mdiobus_child_is_phy(struct device_node *child);
+int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np);
+struct phy_device *of_phy_find_device(struct device_node *phy_np);
+struct phy_device *
+of_phy_connect(struct net_device *dev, struct device_node *phy_np,
+	       void (*hndlr)(struct net_device *), u32 flags,
+	       phy_interface_t iface);
+struct phy_device *
 of_phy_get_and_connect(struct net_device *dev, struct device_node *np,
 		       void (*hndlr)(struct net_device *));
-struct phy_device *of_phy_attach(struct net_device *dev,
-				 struct device_node *phy_np, u32 flags,
-				 phy_interface_t iface);
+struct phy_device *
+of_phy_attach(struct net_device *dev, struct device_node *phy_np,
+	      u32 flags, phy_interface_t iface);
 
-extern struct mii_bus *of_mdio_find_bus(struct device_node *mdio_np);
-extern int of_phy_register_fixed_link(struct device_node *np);
-extern void of_phy_deregister_fixed_link(struct device_node *np);
-extern bool of_phy_is_fixed_link(struct device_node *np);
-extern int of_mdiobus_phy_device_register(struct mii_bus *mdio,
-				     struct phy_device *phy,
+struct mii_bus *of_mdio_find_bus(struct device_node *mdio_np);
+int of_phy_register_fixed_link(struct device_node *np);
+void of_phy_deregister_fixed_link(struct device_node *np);
+bool of_phy_is_fixed_link(struct device_node *np);
+int of_mdiobus_phy_device_register(struct mii_bus *mdio, struct phy_device *phy,
 				   struct device_node *child, u32 addr);
 
 static inline int of_mdio_parse_addr(struct device *dev,