regmap: Prototype regcache_sync()

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index cae69e6..63b3075 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -140,4 +140,5 @@
 int regmap_update_bits(struct regmap *map, unsigned int reg,
 		       unsigned int mask, unsigned int val);
 
+int regcache_sync(struct regmap *map);
 #endif