[NETFITLER]: Add nfnetlink layer.

Introduce "nfnetlink" (netfilter netlink) layer.  This layer is used as
transport layer for all userspace communication of the new upcoming
netfilter subsystems, such as ctnetlink, nfnetlink_queue and some day even
the mythical pkttables ;)

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/Makefile b/net/Makefile
index 8e2bdc0..4a01be8 100644
--- a/net/Makefile
+++ b/net/Makefile
@@ -16,6 +16,7 @@
 obj-$(CONFIG_LLC)		+= llc/
 obj-$(CONFIG_NET)		+= ethernet/ 802/ sched/ netlink/
 obj-$(CONFIG_INET)		+= ipv4/
+obj-$(CONFIG_NETFILTER)		+= netfilter/
 obj-$(CONFIG_XFRM)		+= xfrm/
 obj-$(CONFIG_UNIX)		+= unix/
 ifneq ($(CONFIG_IPV6),)