ASoC: Intel: byt-max98090: Fix mic detect GPIO polarity

Mic detect GPIO is active low when headset microphone is detected. Found
both by debugging and checking the schematics.
Signed-off-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NMark Brown <broonie@linaro.org>

sound/soc/intel/byt-max98090.c

@@ -83,6 +83,7 @@ static struct snd_soc_jack_gpio hs_jack_gpios[] = {
 	{
 		.name		= "mic-gpio",
 		.idx		= 1,
+		.invert		= 1,
 		.report		= SND_JACK_MICROPHONE | SND_JACK_LINEIN,
 		.debounce_time	= 200,
 	},