libusbhost: Add usb_device_get_version()

Change-Id: If2161178e9fe94a94faf01c102ef64f2a72d093b
diff --git a/include/usbhost/usbhost.h b/include/usbhost/usbhost.h
index d26e931..4350ec1 100644
--- a/include/usbhost/usbhost.h
+++ b/include/usbhost/usbhost.h
@@ -156,6 +156,10 @@
  */
 char* usb_device_get_product_name(struct usb_device *device);
 
+/* Returns the version number for the USB device.
+ */
+int usb_device_get_version(struct usb_device *device);
+
 /* Returns the USB serial number for the USB device.
  * Call free() to free the result when you are done with it.
  */