clk: imx: imx8mp-audiomix: use devm_auxiliary_device_create() to simple code

clk: imx: imx8mp-audiomix: use devm_auxiliary_device_create() to simple code

Use helper function devm_auxiliary_device_create() to remove some
boilerplate code.

Reviewed-by: Abel Vesa <abel.vesa@linaro.org>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Shengjiu Wang <shengjiu.wang@gmail.com>
Link: https://lore.kernel.org/r/20251024-auxiliary-v2-1-a353dc9e6b1a@nxp.com
Signed-off-by: Abel Vesa <abel.vesa@linaro.org>