ASoC: tlv320aic3x: Add virtual output pin Detection

Purpose of this virtual Detection pin is to keep codec bias on whenever the
GPIO or jack detection features are needed.

Jack detection needs a mic bias so machine drivers can construct a following
route for instance for keeping the path and codec bias on:

"Input Jack" -> "Mic Bias xV" -> "Detection" -> detection block inside codec.

For the GPIO the machine driver can force the pin on with
snd_soc_dapm_force_enable_pin.

Signed-off-by: Jarkko Nikula <jhnikula@gmail.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

sound/soc/codecs/tlv320aic3x.c

@@ -646,6 +646,14 @@ static const struct snd_soc_dapm_widget aic3x_dapm_widgets[] = {
 	SND_SOC_DAPM_INPUT("LINE1R"),
 	SND_SOC_DAPM_INPUT("LINE2L"),
 	SND_SOC_DAPM_INPUT("LINE2R"),
+
+	/*
+	 * Virtual output pin to detection block inside codec. This can be
+	 * used to keep codec bias on if gpio or detection features are needed.
+	 * Force pin on or construct a path with an input jack and mic bias
+	 * widgets.
+	 */
+	SND_SOC_DAPM_OUTPUT("Detection"),
 };
 
 static const struct snd_soc_dapm_widget aic3007_dapm_widgets[] = {