USB: whci-hcd: provide a endpoint_reset method

Provide a endpoint_reset method to reset sequence number and current
window.  This QHead information can only be changed while the qset is
not in a schedule.

Signed-off-by: David Vrabel <david.vrabel@csr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/host/whci/asl.c b/drivers/usb/host/whci/asl.c
index 958751c..be753f6 100644
--- a/drivers/usb/host/whci/asl.c
+++ b/drivers/usb/host/whci/asl.c
@@ -122,7 +122,8 @@
 		process_inactive_qtd(whc, qset, td);
 	}
 
-	update |= qset_add_qtds(whc, qset);
+	if (!qset->remove)
+		update |= qset_add_qtds(whc, qset);
 
 done:
 	/*