ALSA: hda - make Realtek/Sigmatel/Conexant use the generic unsol event

For less duplication of code between codecs, and to make it easier
in the future to improve code for all codecs simultaneously.

Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>