usb: gadget: configure endpoint according to gadget speed

Add config_ep_by_speed() to configure the endpoint
according to the gadget speed.

Using this function will spare the FDs from handling
the endpoint chosen descriptor.

Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>
Signed-off-by: Felipe Balbi <balbi@ti.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 b78cba4..2014d6b 100644
--- a/include/linux/usb/composite.h
+++ b/include/linux/usb/composite.h
@@ -145,6 +145,9 @@
 
 int usb_interface_id(struct usb_configuration *, struct usb_function *);
 
+int config_ep_by_speed(struct usb_gadget *g, struct usb_function *f,
+			struct usb_ep *_ep);
+
 /**
  * ep_choose - select descriptor endpoint at current device speed
  * @g: gadget, connected and running at some speed