ALSA: hda - Remove fallback to model=ideapad for Lenovo with cx5066

The Lenovo laptops with cx5066 chips seem to work better with
model=auto.  Let's get rid of the fallback to the wrong model.

Bugzilla: https://bugzilla.novell.com/show_bug.cgi?id=738397



Signed-off-by: Takashi Iwai <tiwai@suse.de>