ASoC: atmel-pdmic: add the Pulse Density Modulation Interface Controller

Add driver for the Pulse Density Modulation Interface
Controller. It comes with digitallly controlled gain,
a High-Pass and a SINCC filter.

Signed-off-by: Songjun Wu <songjun.wu@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
4 files changed