ASoC: spear: spdif_in: Staticize non exported struct

The spdif_in_dai struct is not used outside of spdif_in.c, so make it static.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Rajeev Kumar <rajeev-dlh.kumar@st.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/spear/spdif_in.c

@@ -152,7 +152,7 @@ static struct snd_soc_dai_ops spdif_in_dai_ops = {
 	.hw_params	= spdif_in_hw_params,
 };
 
-struct snd_soc_dai_driver spdif_in_dai = {
+static struct snd_soc_dai_driver spdif_in_dai = {
 	.probe = spdif_in_dai_probe,
 	.capture = {
 		.channels_min = 2,