ipv6: support for fib route lwtunnel encap attributes

This patch adds support in ipv6 fib functions to parse Netlink
RTA encap attributes and attach encap state data to rt6_info.

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc include/net/ip6_fib.h
Simple merge

diff --cc net/ipv6/ip6_fib.c
Simple merge

diff --cc net/ipv6/route.c
Simple merge