ASoC: Add TAS67524 quad-channel Class-D amplifier driver

Sen Wang <sen@ti.com> says:

This series adds support for the TI TAS675x (TAS6754, TAS67524)
quad-channel automotive Class-D amplifiers. The devices have an
integrated DSP and load diagnostics, and are controlled over I2C.

Patch 1 adds the dt-binding, patch 2 the codec driver, patch 3 the
ALSA mixer controls documentation, and patch 4 adds the MAINTAINERS
entry.

Tested on AM62D-EVM with a TAS67CD-AEC daughter card. For setup &
test procedures, refer to the GitHub repository.

GitHub: https://github.com/SenWang125/tas67-linux