ipvs: IPv6 extend ICMPv6 handling for future types

Extend handling of ICMPv6, to all none Informational Messages
(via ICMPV6_INFOMSG_MASK).  This actually only extend our handling to
type ICMPV6_PARAMPROB (Parameter Problem), and future types.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>