net: Add Geneve tunneling protocol driver

This adds a device level support for Geneve -- Generic Network
Virtualization Encapsulation. The protocol is documented at
http://tools.ietf.org/html/draft-gross-geneve-01

Only protocol layer Geneve support is provided by this driver.
Openvswitch can be used for configuring, set up and tear down
functional Geneve tunnels.

Signed-off-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: Andy Zhou <azhou@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc include/net/geneve.h
Simple merge

diff --cc include/net/ip_tunnels.h
Simple merge

diff --cc net/ipv4/Kconfig
Simple merge

diff --cc net/ipv4/Makefile
Simple merge

diff --cc net/ipv4/geneve.c
Simple merge