staging: dpaa2-switch: remove obsolete .ndo_fdb_{add|del} callbacks

Since the dpaa2-switch already listens for SWITCHDEV_FDB_ADD_TO_DEVICE /
SWITCHDEV_FDB_DEL_TO_DEVICE events emitted by the bridge, we don't need
the bridge bypass operations, and now is a good time to delete them. All
'bridge fdb' commands need the 'master' flag specified now.

In fact, having the obsolete .ndo_fdb_{add|del} callbacks would even
complicate the bridge leave/join procedures without any real benefit.
Every FDB entry is installed in an FDB ID as far as the hardware is
concerned, and the dpaa2-switch ports change their FDB ID when they join
or leave a bridge. So we would need to manually delete these FDB entries
when the FDB ID changes. That's because, unlike FDB entries added
through switchdev, where the bridge automatically deletes those on
leave, there isn't anybody who will remove the static FDB entries
installed via the bridge bypass operations upon a change in the upper
device.

Note that we still need .ndo_fdb_dump though. The dpaa2-switch does not
emit any interrupts when a new address is learnt, so we cannot keep the
bridge FDB in sync with the hardware FDB. Therefore, we need this
callback to get a chance to print the FDB entries that were dynamically
learnt by our hardware.

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>