reset: imx8mp-audiomix: Add prefix for internal macro

This adds IMX8MP_AUDIOMIX_ prefix to internal macros in order to show
that specific macros are related to audiomix.

Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
Link: https://lore.kernel.org/r/20250311085812.1296243-5-daniel.baluta@nxp.com


Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>