net: dsa: felix: bring the NPI port indirection for host flooding to surface

For symmetry with host FDBs and MDBs where the indirection is now
handled outside the ocelot switch lib, do the same for bridge port
flags (unicast/multicast/broadcast flooding).

The only caller of the ocelot switch lib which uses the NPI port is the
Felix DSA driver.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>