ALSA: hda: Add modelname lookup and fixup for realtek codecs

Facilitate fixup for realtek codecs via modelname lookup of fixup
data.  Fallback to quirk based lookup in absence of model definition.

Signed-off-by: Todd Broch <tbroch@chromium.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>