net: dsa: felix: convert to the new .change_tag_protocol DSA API

In expectation of the new tag_ocelot_8021q tagger implementation, we
need to be able to do runtime switchover between one tagger and another.
So we must structure the existing code for the current NPI-based tagger
in a certain way.

We move the felix_npi_port_init function in expectation of the future
driver configuration necessary for tag_ocelot_8021q: we would like to
not have the NPI-related bits interspersed with the tag_8021q bits.

The conversion from this:

	ocelot_write_rix(ocelot,
			 ANA_PGID_PGID_PGID(GENMASK(ocelot->num_phys_ports, 0)),
			 ANA_PGID_PGID, PGID_UC);

to this:

	cpu_flood = ANA_PGID_PGID_PGID(BIT(ocelot->num_phys_ports));
	ocelot_rmw_rix(ocelot, cpu_flood, cpu_flood, ANA_PGID_PGID, PGID_UC);

is perhaps non-trivial, but is nonetheless non-functional. The PGID_UC
(replicator for unknown unicast) is already configured out of hardware
reset to flood to all ports except ocelot->num_phys_ports (the CPU port
module). All we change is that we use a read-modify-write to only add
the CPU port module to the unknown unicast replicator, as opposed to
doing a full write to the register.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
diff --git a/drivers/net/dsa/ocelot/felix_vsc9959.c b/drivers/net/dsa/ocelot/felix_vsc9959.c
index f9711e6..e944868 100644
--- a/drivers/net/dsa/ocelot/felix_vsc9959.c
+++ b/drivers/net/dsa/ocelot/felix_vsc9959.c
@@ -1467,6 +1467,7 @@ static int felix_pci_probe(struct pci_dev *pdev,
 	ds->ops = &felix_switch_ops;
 	ds->priv = ocelot;
 	felix->ds = ds;
+	felix->tag_proto = DSA_TAG_PROTO_OCELOT;
 
 	err = dsa_register_switch(ds);
 	if (err) {