[PATCH] pull in necessary header files for cdev.h

linux/cdev.h uses struct kobject and other structs and should therefore
include them.  Currently, a module either needs to add the missing includes
itself, or, in case a module includes other headers already, needs to put
<linux/cdev.h> last, which goes against a alphabetically-sorted include
list.
Signed-off-by: Jan Engelhardt <jengelh@gmx.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

include/linux/cdev.h

@@ -2,6 +2,10 @@
 #define _LINUX_CDEV_H
 #ifdef __KERNEL__
 
+#include <linux/kobject.h>
+#include <linux/kdev_t.h>
+#include <linux/list.h>
+
 struct cdev {
 	struct kobject kobj;
 	struct module *owner;