bridge: Allow setting per-{Port, VLAN} neighbor suppression state

Add a new bridge port attribute that allows user space to enable
per-{Port, VLAN} neighbor suppression. Example:

 # bridge -d -j -p link show dev swp1 | jq '.[]["neigh_vlan_suppress"]'
 false
 # bridge link set dev swp1 neigh_vlan_suppress on
 # bridge -d -j -p link show dev swp1 | jq '.[]["neigh_vlan_suppress"]'
 true
 # bridge link set dev swp1 neigh_vlan_suppress off
 # bridge -d -j -p link show dev swp1 | jq '.[]["neigh_vlan_suppress"]'
 false

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>