ASoC: tegra: Add control for the Mic Jack pin

So userspace can enable and disable the external microphone.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/sound/soc/tegra/tegra_max98090.c b/sound/soc/tegra/tegra_max98090.c
index 29ea87c..1f20c2c 100644
--- a/sound/soc/tegra/tegra_max98090.c
+++ b/sound/soc/tegra/tegra_max98090.c
@@ -139,6 +139,7 @@
 static const struct snd_kcontrol_new tegra_max98090_controls[] = {
 	SOC_DAPM_PIN_SWITCH("Headphones"),
 	SOC_DAPM_PIN_SWITCH("Speakers"),
+	SOC_DAPM_PIN_SWITCH("Mic Jack"),
 	SOC_DAPM_PIN_SWITCH("Int Mic"),
 };