ASoC: SOF: mediatek: Add DSP system PM callback for mt8186

Add DSP system PM callback for suspend and resume

Signed-off-by: Allen-KH Cheng <allen-kh.cheng@mediatek.com>
Signed-off-by: Tinghan Shen <tinghan.shen@mediatek.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Yaochun Hung <yc.hung@mediatek.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20220422055659.8738-5-tinghan.shen@mediatek.com


Signed-off-by: Mark Brown <broonie@kernel.org>