usb: cdns3: starfive: don't misuse /** comment

Use a common C comment "/*" instead of "/**" to prevent a warning
from scripts/kernel-doc.

cdns3-starfive.c:23: warning: expecting prototype for cdns3(). Prototype was for USB_STRAP_HOST() instead
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Minda Chen <minda.chen@starfivetech.com>
Cc: Peter Chen <peter.chen@kernel.org>
Cc: Pawel Laszczak <pawell@cadence.com>
Cc: Roger Quadros <rogerq@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:  <linux-usb@vger.kernel.org>
Acked-by: Peter Chen <peter.chen@kernel.org>
Link: https://lore.kernel.org/r/20231206181317.27515-1-rdunlap@infradead.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/cdns3/cdns3-starfive.c

 // SPDX-License-Identifier: GPL-2.0
-/**
+/*
  * cdns3-starfive.c - StarFive specific Glue layer for Cadence USB Controller
  *
  * Copyright (C) 2023 StarFive Technology Co., Ltd.