usb: dwc3: exynos: fix incorrect kernel-doc comment syntax

The opening comment mark '/**' is used for highlighting the beginning of
kernel-doc comments.
The header for drivers/usb/dwc3/dwc3-exynos.c follows this syntax, but the
content inside does not comply with kernel-doc.

This line was probably not meant for kernel-doc parsing, but is parsed
due to the presence of kernel-doc like comment syntax(i.e, '/**'), which
causes unexpected warning from kernel-doc:
"warning: expecting prototype for dwc3(). Prototype was for DWC3_EXYNOS_MAX_CLOCKS() instead"

Provide a simple fix by replacing this occurrence with general comment
format, i.e. '/*', to prevent kernel-doc from parsing it.
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Link: https://lore.kernel.org/r/20210329140318.27742-1-yashsri421@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/dwc3/dwc3-exynos.c

 // SPDX-License-Identifier: GPL-2.0
-/**
+/*
  * dwc3-exynos.c - Samsung Exynos DWC3 Specific Glue layer
  *
  * Copyright (c) 2012 Samsung Electronics Co., Ltd.