ASoC: codecs: tas675x: misc bugfixes and minor changes

Sen Wang <sen@ti.com> says:

Few miscellaneous bug fixes after the initial merge of TAS675x driver, of
which includes:

- Adding READ_ONCE for all concurrent read params
- Corrected kcontrol bits for temperature range
- Corrected conversion notes in the driver documentation

Link: https://patch.msgid.link/20260630183126.2588322-1-sen@ti.com