Merge branch 'bonding-ipv6-NA-NS-monitor'

Hangbin Liu says:

====================
bonding: add IPv6 NS/NA monitor support

This patch add bond IPv6 NS/NA monitor support. A new option
ns_ip6_target is added, which is similar with arp_ip_target.
The IPv6 NS/NA monitor will take effect when there is a valid IPv6
address. Both ARP monitor and NS monitor will working at the same time.

A new extra storage field is added to struct bond_opt_value for IPv6 support.

Function bond_handle_vlan() is split from bond_arp_send() for both
IPv4/IPv6 usage.

To alloc NS message and send out. ndisc_ns_create() and ndisc_send_skb()
are exported.

v1 -> v2:
1. remove sysfs entry[1] and only keep netlink support.

RFC -> v1:
1. define BOND_MAX_ND_TARGETS as BOND_MAX_ARP_TARGETS
2. adjust for reverse xmas tree ordering of local variables
3. remove bond_do_ns_validate()
4. add extra field for bond_opt_value
5. set IS_ENABLED(CONFIG_IPV6) for IPv6 codes

[1] https://lore.kernel.org/netdev/8863.1645071997@famine
====================

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