Driver core: show drivers in /sys/module/

Show the drivers, which belong to the module:
  $ ls -l /sys/module/usbcore/drivers/
  hub -> ../../../bus/usb/drivers/hub
  usb -> ../../../bus/usb/drivers/usb
  usbfs -> ../../../bus/usb/drivers/usbfs

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/include/linux/module.h b/include/linux/module.h
index d1d00ce..9258ffd 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -264,6 +264,7 @@
 	struct module_attribute *modinfo_attrs;
 	const char *version;
 	const char *srcversion;
+	struct kobject *drivers_dir;
 
 	/* Exported symbols */
 	const struct kernel_symbol *syms;