Just like we enabled multicast snooping on the batman-adv client bridge
again, let's do the same for the WAN side.
With one exception: The IGMP/MLD querier is kept disabled to avoid
becoming too "bossy"/"noisy" on a foreign network. The main router on
the WAN side should perform querying and by that enable
IGMP/MLD/snooping if it considers this appropriate there.
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Some drivers (mt76) don't support arbitrary MAC addresses. Use the
addresses provided by the driver (avoiding the primary address) by default,
but fall back to our has-based scheme when the driver doesn't provide
(enough) addresses.
