ASoC: tegra: Add master volume/mute control support

The MVC module has a per channel control bit, based on which it decides
to apply channel specific volume/mute settings. When per channel control
bit is enabled (which is the default HW configuration), all MVC channel
volume/mute can be independently controlled. If the control is disabled,
channel-0 volume/mute setting is applied by HW to all remaining channels.
Thus add support to leverage this HW feature by exposing master controls
for volume/mute.

With this, now there are per channel and master volume/mute controls.
Users need to just use controls which are suitable for their applications.
The per channel control enable/disable is mananged in driver and hidden
from users, so that they need to just worry about respective volume/mute
controls.

Signed-off-by: Sameer Pujar <spujar@nvidia.com>
Link: https://lore.kernel.org/r/1638278605-28225-1-git-send-email-spujar@nvidia.com
Signed-off-by: Mark Brown <broonie@kernel.org>

ASoC: tegra: Add Tegra210 based MVC driver

The Master Volume Control (MVC) provides gain or attenuation to a digital
signal path. It can be used in input or output signal path for per-stream
volume control or it can be used as master volume control. The MVC block
has one input and one output. The input digital stream can be mono or
multi-channel (up to 7.1 channels) stream. An independent mute control is
also included in the MVC block.

This patch registers MVC driver with ASoC framework. The component driver
exposes DAPM widgets, routes and kcontrols for the device. The DAI driver
exposes MVC 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-mvc"
compatible binding.

Signed-off-by: Sameer Pujar <spujar@nvidia.com>
Link: https://lore.kernel.org/r/1631551342-25469-7-git-send-email-spujar@nvidia.com
Signed-off-by: Mark Brown <broonie@kernel.org>