driver core: add #include <linux/sysfs.h> to core files.

This is needed to fix the build on sh systems.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/base/driver.c b/drivers/base/driver.c
index c7efccb..9e29943 100644
--- a/drivers/base/driver.c
+++ b/drivers/base/driver.c
@@ -15,6 +15,7 @@
 #include <linux/errno.h>
 #include <linux/slab.h>
 #include <linux/string.h>
+#include <linux/sysfs.h>
 #include "base.h"
 
 static struct device *next_device(struct klist_iter *i)