ALSA: hda - hdmi: Fix available channel maps missing from TLV

Currently the available channel maps TLV only contains channel maps that
are limited to the traditional 7.1 speakers.

Since the other HDMI channel mapping functions have been fixed to
properly handle all CEA-861-E specified speakers, allow them to be
listed.

Signed-off-by: Anssi Hannula <anssi.hannula@iki.fi>
Signed-off-by: Takashi Iwai <tiwai@suse.de>