ASoC: wm_adsp: Add debug print to note that the DSP has shutdown

It can be useful for debugging purposes to see at what point the DSP has
powered down, so add a message to inform us of this.
Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

sound/soc/codecs/wm_adsp.c

@@ -1679,6 +1679,8 @@ int wm_adsp2_event(struct snd_soc_dapm_widget *w,
 			list_del(&alg_region->list);
 			kfree(alg_region);
 		}
+
+		adsp_dbg(dsp, "Shutdown complete\n");
 		break;
 
 	default: