mlxsw: spectrum: Remove unused traps

Since commit 99724c18 ("mlxsw: spectrum: Introduce support for
router interfaces") we no longer rely on flooding traffic to the CPU in
order to trap packets intended for the host itself. Therefore, the FDB
MC trap can be removed.
Remove traps for protocols that are not supported yet.

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>