ASoC: Make pmdown_time a long

Fixes a warning.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index c2008bc..e1c0336 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -136,7 +136,7 @@
 	struct snd_soc_device *socdev = dev_get_drvdata(dev);
 	struct snd_soc_card *card = socdev->card;
 
-	return sprintf(buf, "%d\n", card->pmdown_time);
+	return sprintf(buf, "%ld\n", card->pmdown_time);
 }
 
 static ssize_t pmdown_time_set(struct device *dev,