net: dsa: vsc73xx: Add bridge support

This patch adds bridge support for the vsc73xx driver.

The vsc73xx requires minimal operations and ithe generic
dsa_tag_8021q_bridge_* API is sufficient.
The forwarding matrix is managed by vsc73xx_port_stp_state_set() ->
vsc73xx_refresh_fwd_map()i routine, which is called immediately after
.port_bridge_join() and .port_bridge_leave().
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
Link: https://patch.msgid.link/20240713211620.1125910-12-paweldembicki@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/dsa/vitesse-vsc73xx-core.c

@@ -691,6 +691,9 @@ static int vsc73xx_setup(struct dsa_switch *ds)
 
 	dev_info(vsc->dev, "set up the switch\n");
 
+	ds->untag_bridge_pvid = true;
+	ds->max_num_bridges = DSA_TAG_8021Q_MAX_NUM_BRIDGES;
+
 	/* Issue RESET */
 	vsc73xx_write(vsc, VSC73XX_BLOCK_SYSTEM, 0, VSC73XX_GLORESET,
 		      VSC73XX_GLORESET_MASTER_RESET);
@@ -1716,6 +1719,8 @@ static const struct dsa_switch_ops vsc73xx_ds_ops = {
 	.get_sset_count = vsc73xx_get_sset_count,
 	.port_enable = vsc73xx_port_enable,
 	.port_disable = vsc73xx_port_disable,
+	.port_bridge_join = dsa_tag_8021q_bridge_join,
+	.port_bridge_leave = dsa_tag_8021q_bridge_leave,
 	.port_change_mtu = vsc73xx_change_mtu,
 	.port_max_mtu = vsc73xx_get_max_mtu,
 	.port_stp_state_set = vsc73xx_port_stp_state_set,