usb: raw-gadget: add copyright

Add copyright to drivers/usb/gadget/legacy/raw_gadget.c.
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Link: https://lore.kernel.org/r/c8937266c4a5da073ac81cd471b18d869c984dfe.1611429174.git.andreyknvl@google.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/gadget/legacy/raw_gadget.c

@@ -3,7 +3,8 @@
  * USB Raw Gadget driver.
  * See Documentation/usb/raw-gadget.rst for more details.
  *
- * Andrey Konovalov <andreyknvl@gmail.com>
+ * Copyright (c) 2020 Google, Inc.
+ * Author: Andrey Konovalov <andreyknvl@gmail.com>
  */
 
 #include <linux/compiler.h>