[ALSA] hda-intel - Support multiple devices

It turned out that there can be multiple HD-audio devices on a single
machine (e.g. on-board audio and HDMI on graphic cards), so we need to
support multiple devices with snd-hda-intel driver.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>