kernel: of-mdio: fix 5.15 fwnode_mdio dependency

Upstream in commit bc1bee3b87ee ("net: mdiobus: Introduce
fwnode_mdiobus_register_phy()") in version 5.14 introduced new
dependency:

 Package kmod-of-mdio is missing dependencies for the following libraries:

  fwnode_mdio.ko

Signed-off-by: Petr Štetiar <ynezz@true.cz>

package/kernel/linux/modules/netdevices.mk

@@ -1057,7 +1057,8 @@ define KernelPackage/of-mdio
   KCONFIG:=CONFIG_OF_MDIO
   FILES:= \
 	$(LINUX_DIR)/drivers/of/of_mdio.ko@lt5.10 \
-	$(LINUX_DIR)/drivers/net/mdio/of_mdio.ko@ge5.10
+	$(LINUX_DIR)/drivers/net/mdio/of_mdio.ko@ge5.10 \
+	$(LINUX_DIR)/drivers/net/mdio/fwnode_mdio.ko@ge5.15
   AUTOLOAD:=$(call AutoLoad,41,of_mdio)
 endef