staging: dpaa2-switch: remove broken learning and flooding support

This patch is removing the current configuration of learning and
flooding states per switch port because they are essentially broken in
terms of integration with the switchdev APIs and the bridge
understanding of these states.

First of all, the learning state is a per switch port configuration
while the dpaa2-switch driver was using it to configure the entire
bridging domain. This is broken since the software learning state could
be out of sync with the hardware state when ports from the same bridging
domain are configured by the user with different learning parameters.

The BR_FLOOD flag has been misinterpreted as well. Instead of denoting
whether unicast traffic for which there is no FDB entry will be flooded
towards a given port, the dpaa2-switch used the flag to configure
whether or not a frame with an unknown destination received on a given
port should be flooded or not. In summary, it was used as ingress
setting instead of a egress one.

Also, remove the unnecessary call to dpsw_if_set_broadcast() and the API
definition. The HW default is to let all switch ports to be able to
flood broadcast traffic thus there is no need to call the API again.

Instead of trying to patch things up, just remove the support for the
moment so that we'll add it back cleanly once the driver is out of
staging.

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>