ASoC: nuc900: export nuc900_ac97_data

The symbol "nuc900_ac97_data" is used by the nuc900_pcm driver,
which may be a loadable module, so we should export it.

If one tries to build SND_SOC_NUC900 without SND_SOC_NUC900_AC97,
the kernel fails to link because of the reference to nuc900_ac97_data.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Xia Kaixu <kaixu.xia@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/sound/soc/nuc900/nuc900-ac97.c b/sound/soc/nuc900/nuc900-ac97.c
index 8987bf9..f2f67942 100644
--- a/sound/soc/nuc900/nuc900-ac97.c
+++ b/sound/soc/nuc900/nuc900-ac97.c
@@ -28,6 +28,7 @@
 
 static DEFINE_MUTEX(ac97_mutex);
 struct nuc900_audio *nuc900_ac97_data;
+EXPORT_SYMBOL_GPL(nuc900_ac97_data);
 
 static int nuc900_checkready(void)
 {