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>

sound/soc/tegra/tegra_max98090.c

@@ -139,6 +139,7 @@ static const struct snd_soc_dapm_widget tegra_max98090_dapm_widgets[] = {
 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"),
 };