Merge branch 'lwt-ipv6'

Jiri Benc says:

====================
lwtunnel: per route ipv6 support for vxlan

v3: Moved LWTUNNEL_ENCAP_IP6 definition in patch 13.
v2: Fixed issues in patch 4 pointed out by Alexei.

This series enables IPv6 tunnels based on lwtunnel infrastructure. Only
vxlan is supported for now.

Tested in all combinations of IPv4 over IPv6, IPv6 over IPv4 and IPv6 over
IPv6.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>