of/mdio: Add dummy functions in of_mdio.h.

This patch adds dummy functions in of_mdio.h, so that driver need not
ifdef there code with CONFIG_OF.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/of_mdio.h

@@ -12,6 +12,7 @@
 #include <linux/phy.h>
 #include <linux/of.h>
 
+#ifdef CONFIG_OF
 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,
@@ -24,4 +25,36 @@ extern struct phy_device *of_phy_connect_fixed_link(struct net_device *dev,
 
 extern struct mii_bus *of_mdio_find_bus(struct device_node *mdio_np);
 
+#else /* CONFIG_OF */
+int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
+{
+	return -ENOSYS;
+}
+
+struct phy_device *of_phy_find_device(struct device_node *phy_np)
+{
+	return NULL;
+}
+
+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)
+{
+	return NULL;
+}
+
+struct phy_device *of_phy_connect_fixed_link(struct net_device *dev,
+					 void (*hndlr)(struct net_device *),
+					 phy_interface_t iface)
+{
+	return NULL;
+}
+
+struct mii_bus *of_mdio_find_bus(struct device_node *mdio_np)
+{
+	return NULL;
+}
+#endif /* CONFIG_OF */
+
 #endif /* __LINUX_OF_MDIO_H */