net: dsa: lantiq_gswip: use simple HSR offload helpers

net: dsa: lantiq_gswip: use simple HSR offload helpers

Both the "gswip" and "gsw1xx" protocols 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: Hauke Mehrtens <hauke@hauke-m.de>
Cc: Daniel Golle <daniel@makrotopia.org>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://patch.msgid.link/20251130131657.65080-10-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>