arm64: tegra: Add Tegra264 audio support

arm64: tegra: Add Tegra264 audio support

- Add the audio devices for the Tegra264 SoC in the tegra264.dtsi file,
  which includes sound, HDA and APE(Audio Processing Engine) subsystem
  nodes.
  APE subsystem includes,
   - I/O interfaces such as I2S, DMIC and DSPK (all the available
     instances).
   - HW accelerators such as ASRC, OPE, MVC, SFC, AMX, ADX and Mixer (all
     the available instances).
   - ADMA controller and Interrupt controllers.

- Enable the audio nodes in tegra264-p3971.dtsi platform DT file.

Signed-off-by: sheetal <sheetal@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>