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>

drivers/net/phy/broadcom.c

@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  *	drivers/net/phy/broadcom.c
  *
@@ -7,11 +8,6 @@
  *	Copyright (c) 2006  Maciej W. Rozycki
  *
  *	Inspired by code written by Amy Fong.
- *
- *	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.
  */
 
 #include "bcm-phy-lib.h"