usb: dwc2: Fix kernel doc's warnings.

Added descriptions for all not described parameters.
Fix all kernel doc's warnings.

Acked-by: Minas Harutyunyan <hminas@synopsys.com>
Signed-off-by: Grigor Tovmasyan <tovmasya@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc2/debug.h

@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0
-/**
+/*
  * debug.h - Designware USB2 DRD controller debug header
  *
  * Copyright (C) 2015 Intel Corporation