USB: Composite framework: Add suspended sysfs entry

This patch adds a sysfs entry (/sys/devices/platform/_UDC_/gadget/suspended) to
show the suspend state of an USB composite gadget.

Signed-off-by: Fabien Chouteau <fabien.chouteau@barco.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h
index 738ea1a..139353e 100644
--- a/include/linux/usb/composite.h
+++ b/include/linux/usb/composite.h
@@ -326,6 +326,7 @@
 
 	/* private: */
 	/* internals */
+	unsigned int			suspended:1;
 	struct usb_device_descriptor	desc;
 	struct list_head		configs;
 	struct usb_composite_driver	*driver;