regulator: consumer.h - fix build when consumer.h is #included first.

consumer.h requires device.h for stand alone build.

Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
diff --git a/include/linux/regulator/consumer.h b/include/linux/regulator/consumer.h
index 490c5b3..030d922 100644
--- a/include/linux/regulator/consumer.h
+++ b/include/linux/regulator/consumer.h
@@ -35,6 +35,8 @@
 #ifndef __LINUX_REGULATOR_CONSUMER_H_
 #define __LINUX_REGULATOR_CONSUMER_H_
 
+#include <linux/device.h>
+
 /*
  * Regulator operating modes.
  *