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/arch/arm/mach-tegra/gpu.c b/arch/arm/mach-tegra/gpu.c
index c7d705d..0dbddd4 100644
--- a/arch/arm/mach-tegra/gpu.c
+++ b/arch/arm/mach-tegra/gpu.c
@@ -1,17 +1,7 @@
 /*
  * Copyright (c) 2014-2015, NVIDIA CORPORATION.  All rights reserved.
  *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
+ * SPDX-License-Identifier:	GPL-2.0
  */
 
 /* Tegra vpr routines */