mlxsw: spectrum: Add another flood table for vFIDs

We previously used only one flood table for packets classified to vFIDs.
However, since we are going to add support for bridges between VLAN
interfaces (mapped to vFIDs) we need to add one more flood table.

That way we can separate the flooding domain of unknown unicast traffic
from all the rest and support flood control (as we do with the 802.1Q
bridge).

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>