Add documentation to the sound directory of the
device-tree bindings for the Maxim MAX98357A audio
DAC.
Signed-off-by: NKenneth Westfield <kwestfie@codeaurora.org>
Acked-by: NBanajit Goswami <bgoswami@codeaurora.org>
Signed-off-by: NMark Brown <broonie@kernel.org>