ASoC: Enhance default WM8958 microphone detection

Actively manage the detection rate for microphones with WM8958, providing
improved power consumption and maximising the benefit from the hardware
debounce.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/sound/soc/codecs/wm8994.h b/sound/soc/codecs/wm8994.h
index f4f1355..1087425 100644
--- a/sound/soc/codecs/wm8994.h
+++ b/sound/soc/codecs/wm8994.h
@@ -126,6 +126,8 @@
 	struct soc_enum enh_eq_enum;
 
 	struct wm8994_micdet micdet[2];
+	bool detecting;
+	bool jack_mic;
 
 	wm8958_micdet_cb jack_cb;
 	void *jack_cb_data;