net: phy: constify fwnode_get_phy_node() fwnode argument

fwnode_get_phy_node() does not motify the fwnode structure, so make
the argument const,

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: Russell King (Oracle)

drivers/net/phy/phy_device.c

@@ -3057,7 +3057,7 @@ EXPORT_SYMBOL_GPL(device_phy_find_device);
  * and "phy-device" are not supported in ACPI. DT supports all the three
  * named references to the phy node.
  */
-struct fwnode_handle *fwnode_get_phy_node(struct fwnode_handle *fwnode)
+struct fwnode_handle *fwnode_get_phy_node(const struct fwnode_handle *fwnode)
 {
 	struct fwnode_handle *phy_node;
 

include/linux/phy.h

@@ -1547,7 +1547,7 @@ int fwnode_get_phy_id(struct fwnode_handle *fwnode, u32 *phy_id);
 struct mdio_device *fwnode_mdio_find_device(struct fwnode_handle *fwnode);
 struct phy_device *fwnode_phy_find_device(struct fwnode_handle *phy_fwnode);
 struct phy_device *device_phy_find_device(struct device *dev);
-struct fwnode_handle *fwnode_get_phy_node(struct fwnode_handle *fwnode);
+struct fwnode_handle *fwnode_get_phy_node(const struct fwnode_handle *fwnode);
 struct phy_device *get_phy_device(struct mii_bus *bus, int addr, bool is_c45);
 int phy_device_register(struct phy_device *phy);
 void phy_device_free(struct phy_device *phydev);