ASoC: tegra: Add Tegra210 based Mixer driver

The Mixer supports mixing of up to ten 7.1 audio input streams and
generate five outputs (each of which can be any combination of the
ten input streams)

This patch registers Mixer driver with ASoC framework. The component
driver exposes DAPM widgets, routes and kcontrols for the device.
The DAI driver exposes Mixer interfaces, which can be used to connect
different components in the ASoC layer. Makefile and Kconfig support
is added to allow build the driver. It can be enabled in the DT via
"nvidia,tegra210-amixer" compatible binding.

Signed-off-by: Sameer Pujar <spujar@nvidia.com>
Link: https://lore.kernel.org/r/1631551342-25469-11-git-send-email-spujar@nvidia.com


Signed-off-by: Mark Brown <broonie@kernel.org>