net: dsa: reference count the FDB addresses at the cross-chip notifier level
The same concerns expressed for host MDB entries are valid for host FDBs
just as well:
- in the case of multiple bridges spanning the same switch chip, deleting
a host FDB entry that belongs to one bridge will result in breakage to
the other bridge
- not deleting FDB entries across DSA links means that the switch's
hardware tables will eventually run out, given enough wear&tear
So do the same thing and introduce reference counting for CPU ports and
DSA links using the same data structures as we have for MDB entries.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>