media: meson-ir-tx: remove incorrect doc comment

Do not use kernel-doc "/**" notation when the comment is not in
kernel-doc format. This fixes a sparse warning.
Suggested-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

drivers/media/rc/meson-ir-tx.c

 // SPDX-License-Identifier: GPL-2.0-only
-/**
+/*
  * meson-ir-tx.c - Amlogic Meson IR TX driver
  *
  * Copyright (c) 2021, SberDevices. All Rights Reserved.