Add more SPDX-License-Identifier tags

In a number of places we had wordings of the GPL (or LGPL in a few
cases) license text that were split in such a way that it wasn't caught
previously.  Convert all of these to the correct SPDX-License-Identifier
tag.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/include/ds4510.h b/include/ds4510.h
index 40480af..e54db35 100644
--- a/include/ds4510.h
+++ b/include/ds4510.h
@@ -1,19 +1,7 @@
 /*
  * Copyright 2008 Extreme Engineering Solutions, Inc.
  *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * Version 2 as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
- * MA 02111-1307 USA
+ * SPDX-License-Identifier:	GPL-2.0
  */
 
 #ifndef __DS4510_H_