net: dsa: bcm_sf2: Defer port enabling to calling port_enable

There is no need to configure the enabled ports once in bcm_sf2_sw_setup() and
then a second time around when dsa_switch_ops::port_enable is called, just do
it when port_enable is called which is better in terms of power consumption and
correctness.

Reviewed-by: Vivien Didelot <[e-mail]>
Signed-off-by: Florian Fainelli <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/dsa/bcm_sf2.c

···
 	struct bcm_sf2_priv *priv = bcm_sf2_to_priv(ds);
 	unsigned int port;
 
-	/* Enable all valid ports and disable those unused */
+	/* Disable unused ports and configure IMP port */
 	for (port = 0; port < priv->hw_params.num_ports; port++) {
-		/* IMP port receives special treatment */
-		if ((1 << port) & ds->enabled_port_mask)
-			bcm_sf2_port_setup(ds, port, NULL);
-		else if (dsa_is_cpu_port(ds, port))
+		if (dsa_is_cpu_port(ds, port))
 			bcm_sf2_imp_setup(ds, port);
-		else
+		else if (!((1 << port) & ds->enabled_port_mask))
 			bcm_sf2_port_disable(ds, port, NULL);
 	}