pca953x: minor include cleanup

linux/i2c/pca953x.h is a very bare include file.  Fix check for multiple
includes of linux/i2c/pca953x.h, and add dependent includes into the
header file.
Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Jean Delvare <khali@linux-fr.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/i2c/pca953x.h

+#ifndef _LINUX_PCA953X_H
+#define _LINUX_PCA953X_H
+
+#include <linux/types.h>
+#include <linux/i2c.h>
+
 /* platform data for the PCA9539 16-bit I/O expander driver */
 
 struct pca953x_platform_data {
@@ -17,3 +23,5 @@ struct pca953x_platform_data {
 				void *context);
 	char		**names;
 };
+
+#endif /* _LINUX_PCA953X_H */