build/kernel: remove WireGuard module, for now we support go as well; closes #376

And go doesn't work if a module is installed.  While here split the
plugins into separate code bases as there will be work incoming for
the kernel variant.

build/kernel.sh

@@ -67,6 +67,7 @@ SRCCONF=${CONFIGDIR}/src.conf
 ${SRCDEBUG}
 __MAKE_CONF=
 ${MAKE_ARGS_DEV}
+WITHOUT_MODULES=if_wg
 "
 
 ${ENV_FILTER} make -s -C${SRCDIR} -j${CPUS} kernel-toolchain ${MAKE_ARGS}

config/23.7/plugins.conf

@@ -49,8 +49,8 @@ net/tayga					arm
 net/udpbroadcastrelay				arm
 net/upnp
 net/vnstat					arm
-net/wireguard@go				arm
-net/wireguard@kmod				arm
+net/wireguard					arm
+net/wireguard-go				arm
 net/wol
 net/zerotier					arm
 security/acme-client