net: dsa: hellcreek: use simple HSR offload helpers

The "hellcreek" tagging protocol uses dsa_xmit_port_mask(), which means
we can offload HSR packet duplication on transmit. Enable that feature.

Cc: Kurt Kanzenbach <[e-mail]>
Signed-off-by: Vladimir Oltean <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

drivers/net/dsa/hirschmann/hellcreek.c

···
 	.port_vlan_filtering   = hellcreek_vlan_filtering,
 	.setup		       = hellcreek_setup,
 	.teardown	       = hellcreek_teardown,
+	.port_hsr_join	       = dsa_port_simple_hsr_join,
+	.port_hsr_leave	       = dsa_port_simple_hsr_leave,
 };
 
 static int hellcreek_probe(struct platform_device *pdev)