wifi: rtw89: mac: add dummy handler of MAC C2H event class 27

The newer firmware add new C2H event class 27, which is to report WiFi
role status. Since rtw89 doesn't use the status yet, add a dummy handler
to avoid warning:

  rtw89_8922ae 0000:03:00.0: MAC c2h class 27 func 0 not support

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20250606020302.16873-5-pkshih@realtek.com