kernel: netdev: make kmod-of-mdio conflict with x86

CONFIG_MDIO_OF depends on CONFIG_OF which is not enabled for x86.

Fixes builds of x86 with Kernel 5.10 due to unresolved dependencies.

Signed-off-by: David Bauer <[email protected]>

package/kernel/linux/modules/netdevices.mk

@@ -1006,7 +1006,7 @@ $(eval $(call KernelPackage,forcedeth))
 define KernelPackage/of-mdio
   SUBMENU:=$(NETWORK_DEVICES_MENU)
   TITLE:=OpenFirmware MDIO support
-  DEPENDS:=+kmod-libphy
+  DEPENDS:=+kmod-libphy @!TARGET_x86
   KCONFIG:=CONFIG_OF_MDIO
   FILES:= \
 	$(LINUX_DIR)/drivers/net/phy/fixed_phy.ko \