A step toward offloading IPv6 routing, this adds an additional
multicast routing table meant for IPv6 [with its underlying TCAM
region] and populates the default rule for IPv6 multicast packets.

Following this, ingress IPv6 multicast packets would be trapped and
delivered to the host CPU.
Signed-off-by: NYuval Mintz <yuvalm@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>