Bluetooth: btrsi: use non-kernel-doc comment for copyright

kernel-doc complains about a non-kernel-doc comment that uses "/**"
to begin the comment, so change it to just "/*".

drivers/bluetooth/btrsi.c:2: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
    * Copyright (c) 2017 Redpine Signals Inc.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Aditya Srivastava <yashsri421@gmail.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Cc: linux-bluetooth@vger.kernel.org
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org
Cc: Prameela Rani Garnepudi <prameela.j04cs@gmail.com>
Cc: Sanjay Kumar Konduri <sanjay.konduri@redpinesignals.com>
Cc: Siva Rebbagondla <siva.rebbagondla@redpinesignals.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

drivers/bluetooth/btrsi.c

-/**
+/*
  * Copyright (c) 2017 Redpine Signals Inc.
  *
  * Permission to use, copy, modify, and/or distribute this software for any