ALSA: hda/cs8409: Rewrite to new probe method

Convert the CS8409 codec driver to use the new hda_codec_ops probe.
The Dolphin support needs an override of unsol_event callback, and
redirect via spec->unsol_event function pointer for now.

Other than that, no functional changes.

Reviewed-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20250709160434.1859-17-tiwai@suse.de