net: ocelot: call ocelot_netdevice_bridge_join when joining a bridged LAG

Similar to the DSA situation, ocelot supports LAG offload but treats
this scenario improperly:

ip link add br0 type bridge
ip link add bond0 type bond
ip link set bond0 master br0
ip link set swp0 master bond0

We do the same thing as we do there, which is to simulate a 'bridge join'
on 'lag join', if we detect that the bonding upper has a bridge upper.

Again, same as DSA, ocelot supports software fallback for LAG, and in
that case, we should avoid calling ocelot_netdevice_changeupper.

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