net: sparx5: Use Switchdev fdb events for managing fdb entries

Changes the handling of fdb entries to use Switchdev events,
instead of the previous "sync_bridge" and "sync_port" which
only run when adding or removing VLANs on the bridge.

Signed-off-by: Casper Andersson <casper.casan@gmail.com>
Link: https://lore.kernel.org/r/20220314160918.4rfrrfgmbsf2pxl3@wse-c0155
Signed-off-by: Jakub Kicinski <kuba@kernel.org>