net: bridge: make nbp_switchdev_unsync_objs() follow reverse order of sync()

There may be switchdev drivers that can add/remove a FDB or MDB entry
only as long as the VLAN it's in has been notified and offloaded first.
The nbp_switchdev_sync_objs() method satisfies this requirement on
addition, but nbp_switchdev_unsync_objs() first deletes VLANs, then
deletes MDBs and FDBs. Reverse the order of the function calls to cater
to this requirement.

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