kernel: add kmod-fou

Once installed fou kernel module allows you to use FOU (Foo over UDP)
and GUE (Generic UDP encapsulation) tunnel protocols.

To get ip fou command working you also need to install ip-full.

Signed-off-by: Filip Moc <lede@moc6.cz>

package/kernel/linux/modules/netsupport.mk

@@ -434,6 +434,28 @@ endef
 $(eval $(call KernelPackage,sit))
 
 
+define KernelPackage/fou
+  SUBMENU:=$(NETWORK_SUPPORT_MENU)
+  TITLE:=FOU and GUE decapsulation
+  DEPENDS:= \
+	+kmod-iptunnel \
+	+kmod-udptunnel4 \
+	+IPV6:kmod-udptunnel6
+  KCONFIG:= \
+	CONFIG_NET_FOU \
+	CONFIG_NET_FOU_IP_TUNNELS=y
+  FILES:=$(LINUX_DIR)/net/ipv4/fou.ko
+  AUTOLOAD:=$(call AutoProbe,fou)
+endef
+
+define KernelPackage/fou/description
+ Kernel module for FOU (Foo over UDP) and GUE (Generic UDP Encapsulation) tunnelling.
+ Requires Kernel 3.18 or newer.
+endef
+
+$(eval $(call KernelPackage,fou))
+
+
 define KernelPackage/ip6-tunnel
   SUBMENU:=$(NETWORK_SUPPORT_MENU)
   TITLE:=IP-in-IPv6 tunnelling