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" <alsi@bang-olufsen.dk>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Link: https://patch.msgid.link/20251130131657.65080-9-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>