treewide: add support for building kernel modules used by Gluon into the kernel

package/gluon-client-bridge/Makefile

package/gluon-core/Config.in

package/gluon-core/Makefile

package/gluon-ebtables-limit-arp/Makefile

package/gluon-ebtables/Makefile

package/gluon-mesh-batman-adv/Makefile

package/gluon-mesh-vpn-core/Makefile

package/gluon-mesh-vpn-fastd/Makefile

package/gluon-mesh-vpn-tunneldigger/Makefile

...lude-kernel.mk-build-kmod-packages-with-empty-FILES.patch