This patch adds the support for the generic auto-parser to AD codec
driver.  For AD1988, the old code is replaced simply with the new
generic parser.  For other codecs, new model "auto" is added and
directed to use the generic parser.

No fixup codes have been implemented yet as of now.  Eventually we'd
replace each static quirk with the generic parser + fixup.
Signed-off-by: Takashi Iwai <tiwai@suse.de>