net: dsa: realtek: use simple HSR offload helpers

All known Realtek protocols: "rtl4a", "rtl8_4" and "rtl8_4t" use
dsa_xmit_port_mask(), so they are compatible with accelerating TX packet
duplication for HSR rings.

Enable that feature by setting the port_hsr_join() and port_hsr_leave()
operations to the simple helpers provided by DSA.

Cc: "Alvin Šipraga" <[e-mail]>
Signed-off-by: Vladimir Oltean <[e-mail]>
Reviewed-by: Linus Walleij <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

drivers/net/dsa/realtek/rtl8365mb.c

···
 	.get_stats64 = rtl8365mb_get_stats64,
 	.port_change_mtu = rtl8365mb_port_change_mtu,
 	.port_max_mtu = rtl8365mb_port_max_mtu,
+	.port_hsr_join = dsa_port_simple_hsr_join,
+	.port_hsr_leave = dsa_port_simple_hsr_leave,
 };
 
 static const struct realtek_ops rtl8365mb_ops = {

drivers/net/dsa/realtek/rtl8366rb.c

···
 	.port_fast_age = rtl8366rb_port_fast_age,
 	.port_change_mtu = rtl8366rb_change_mtu,
 	.port_max_mtu = rtl8366rb_max_mtu,
+	.port_hsr_join = dsa_port_simple_hsr_join,
+	.port_hsr_leave = dsa_port_simple_hsr_leave,
 };
 
 static const struct realtek_ops rtl8366rb_ops = {