ASoC: tegra: Add Tegra210 based AMX driver

The Audio Multiplexer (AMX) block can multiplex up to four input streams
each of which can have maximum 16 channels and generate an output stream
with maximum 16 channels. A byte RAM helps to form an output frame by
any combination of bytes from the input frames.

This patch registers AMX driver with ASoC framework. The component driver
exposes DAPM widgets, routes and kcontrols for the device. The DAI driver
exposes AMX 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-amx" for
Tegra210 and Tegra186. For Tegra194 and later, "nvidia,tegra194-amx" can
be used.

Signed-off-by: Sameer Pujar <spujar@nvidia.com>
Link: https://lore.kernel.org/r/1631551342-25469-9-git-send-email-spujar@nvidia.com


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