ASoC: tegra: Staticise tegra_i2s_dai and tegra_spdif_dai

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/sound/soc/tegra/tegra_spdif.c b/sound/soc/tegra/tegra_spdif.c
index abe606b..1bd07d1 100644
--- a/sound/soc/tegra/tegra_spdif.c
+++ b/sound/soc/tegra/tegra_spdif.c
@@ -232,7 +232,7 @@
 	.trigger	= tegra_spdif_trigger,
 };
 
-struct snd_soc_dai_driver tegra_spdif_dai = {
+static struct snd_soc_dai_driver tegra_spdif_dai = {
 	.name = DRV_NAME,
 	.probe = tegra_spdif_probe,
 	.playback = {