phy: mvebu-cp110-comphy: switch to SPDX identifier

Use the appropriate SPDX license identifier and drop the license text.
This patch is only cosmetic.
Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

drivers/phy/marvell/phy-mvebu-cp110-comphy.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) 2017 Marvell
  *
  * Antoine Tenart <antoine.tenart@free-electrons.com>
- *
- * This file is licensed under the terms of the GNU General Public
- * License version 2. This program is licensed "as is" without any
- * warranty of any kind, whether express or implied.
  */
 
 #include <linux/io.h>