net: dsa: sja1105: remove sp->dp

It looks like this field was never used since its introduction in commit
227d07a0 ("net: dsa: sja1105: Add support for traffic through
standalone ports") remove it.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/dsa/sja1105/sja1105_main.c

@@ -2965,7 +2965,6 @@ static int sja1105_setup_ports(struct sja1105_private *priv)
 			continue;
 
 		dp->priv = sp;
-		sp->dp = dp;
 		sp->data = tagger_data;
 		slave = dp->slave;
 		kthread_init_work(&sp->xmit_work, sja1105_port_deferred_xmit);

include/linux/dsa/sja1105.h

@@ -65,7 +65,6 @@ struct sja1105_port {
 	struct kthread_work xmit_work;
 	struct sk_buff_head xmit_queue;
 	struct sja1105_tagger_data *data;
-	struct dsa_port *dp;
 	bool hwts_tx_en;
 };