A simple conversion from a plain text file.
Put to hd-audio subdirectory.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

A conversion from a simple text file.
Put to hd-audio subdirectory with a rename.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

A simple reformat with the description list of ReST, and the content
was kept as is, but renamed as Documentation/sound/hd-audio/models.rst.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The original HD-Audio.txt was already in asciidoc format, so it's a
simple conversion in the end.

A new subdirectory, Documentation/sound/hd-audio, is created and the
document is moved there with another file name to match better with
the recent Documentation tree structure.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>