mlxsw: spectrum: Add mlxsw_sp_fid_ops.fdb_clear_offload

If there are any offloaded FDB entries at bridge master of an NVE device
at the time that it's un-offloaded, their offloaded marks need to be
cleared. How that is done depends on whether the bridge in question is
vlan aware. Therefore add a per-FID-type operation.

Implement the operation for the 802.1q and 802.1d bridges.

Add and publish a function mlxsw_sp_fid_fdb_clear_offload() to dispatch
to the new operation according to FID type.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>