Add DT nodes for following AHUB devices:
 * SFC (Sampling Frequency Converter)
 * MVC (Master Volume Control)
 * AMX (Audio Multiplexer)
 * ADX (Audio Demultiplexer)
 * Mixer

Above devices are added for Tegra210, Tegra186 and Tegra194 generations
of Tegra SoC.
Signed-off-by: Sameer Pujar <spujar@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>