Add bindings that describes audio settings to support
Digital Filter for pulse density modulation(PDM) microphone.
Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Arnaud Pouliquen