mlxsw: spectrum_switchdev: Save mids list per bridge device

mlxsw: spectrum_switchdev: Save mids list per bridge device

Instead of saving all the mids in the same list, save them per vlan
device. This change allows a more efficient mid find.
Also, in the next patches, there will be added a lot of loops over all the
mids in bridge device for multicast disable, mrouter change and ndb flush.

Signed-off-by: Nogah Frankel <nogahf@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>