Yet another simple conversion from a plain text file.
Put to cards directory.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Add documentation for the controls present in the SPDIF input
controller driver
Signed-off-by: NDamien.Horsley <Damien.Horsley@imgtec.com>
Signed-off-by: NMark Brown <broonie@kernel.org>