ASoC: jack: Basic GPIO descriptor conversion

This patch does basic GPIO descriptor conversion to soc-jack. Even the GPIOs
are still passed and requested using legacy GPIO numbers the driver
internals are converted to use GPIO descriptor API.

Motivation for this is to prepare soc-jack so that it will allow registering
jack GPIO pins using both GPIO descriptors and legacy GPIO numbers.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/include/sound/soc.h b/include/sound/soc.h
index 0b83168..c6bd40f 100644
--- a/include/sound/soc.h
+++ b/include/sound/soc.h
@@ -606,6 +606,7 @@
 
 	struct snd_soc_jack *jack;
 	struct delayed_work work;
+	struct gpio_desc *desc;
 
 	void *data;
 	int (*jack_status_check)(void *data);