net: phy: Convert some PHY and MDIO driver files to SPDX headers

Where the license text and the MODULE_LICENSE() value agree, convert
to using an SPDX header, removing the license text.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/phy/national.c b/drivers/net/phy/national.c
index 139bed2..42282a8 100644
--- a/drivers/net/phy/national.c
+++ b/drivers/net/phy/national.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * drivers/net/phy/national.c
  *
@@ -7,12 +8,6 @@
  * Maintainer: Giuseppe Cavallaro <peppe.cavallaro@st.com>
  *
  * Copyright (c) 2008 STMicroelectronics Limited
- *
- * This program is free software; you can redistribute  it and/or modify it
- * under  the terms of  the GNU General  Public License as published by the
- * Free Software Foundation;  either version 2 of the  License, or (at your
- * option) any later version.
- *
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt