reset: imx8mp-audiomix: Add support for DSP run/stall

reset: imx8mp-audiomix: Add support for DSP run/stall

We can Run/Stall the DSP via audio block control bits found in audiomix.
Implement this functionality using the reset controller and use assert
for Stall and deassert for Run.

Reviewed-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Link: https://lore.kernel.org/r/20250311085812.1296243-8-daniel.baluta@nxp.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>