mmc: make mmc_dev_to_card() macro public

Conversion from struct device to struct mmc_card is used more than in one
place.  Due to this it's better to have public macro for such thing.

Signed-off-by: Andy Shevchenko <ext-andriy.shevchenko@nokia.com>
Cc: Adrian Hunter <adrian.hunter@nokia.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 6b75250..71acf19 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -173,6 +173,8 @@
 #define mmc_card_name(c)	((c)->cid.prod_name)
 #define mmc_card_id(c)		(dev_name(&(c)->dev))
 
+#define dev_to_mmc_card(d)	container_of(d, struct mmc_card, dev)
+
 #define mmc_list_to_card(l)	container_of(l, struct mmc_card, node)
 #define mmc_get_drvdata(c)	dev_get_drvdata(&(c)->dev)
 #define mmc_set_drvdata(c,d)	dev_set_drvdata(&(c)->dev, d)