greybus: audio: fix some sparse static warnings

This makes some functions and structures static, as warned by sparse, as
they don't need to be global.
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Reviewed-by: Alex Elder <elder@linaro.org>

drivers/staging/greybus/audio-dai.c

@@ -59,7 +59,7 @@ static const struct snd_soc_dai_ops gb_dai_ops = {
 	.set_fmt	= gb_dai_set_fmt,
 };
 
-struct snd_soc_dai_driver gb_cpu_dai = {
+static struct snd_soc_dai_driver gb_cpu_dai = {
 	.name			= "gb-cpu-dai",
 	.playback = {
 		.rates		= GB_RATES,

drivers/staging/greybus/audio-pcm.c

@@ -235,7 +235,7 @@ static int gb_pcm_new(struct snd_soc_pcm_runtime *rtd)
 			PREALLOC_BUFFER, PREALLOC_BUFFER_MAX);
 }
 
-struct snd_soc_platform_driver gb_soc_platform = {
+static struct snd_soc_platform_driver gb_soc_platform = {
 	.ops		= &gb_pcm_ops,
 	.pcm_new	= gb_pcm_new,
 	.pcm_free	= gb_pcm_free,

drivers/staging/greybus/audio.c

@@ -93,7 +93,7 @@ struct gb_card_info_object {
 };
 
 
-struct asoc_simple_card_info *setup_card_info(int device_count)
+static struct asoc_simple_card_info *setup_card_info(int device_count)
 {
 	struct gb_card_info_object *obj;
 
@@ -125,7 +125,7 @@ struct asoc_simple_card_info *setup_card_info(int device_count)
 	return &obj->card_info;
 }
 
-void free_card_info(struct asoc_simple_card_info *ci)
+static void free_card_info(struct asoc_simple_card_info *ci)
 {
 	struct gb_card_info_object *obj;