bcm2835/rpi: add SPDX license tags for some files

Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
diff --git a/arch/arm/include/asm/arch-bcm2835/sdhci.h b/arch/arm/include/asm/arch-bcm2835/sdhci.h
index a4f867b..da4d5cd 100644
--- a/arch/arm/include/asm/arch-bcm2835/sdhci.h
+++ b/arch/arm/include/asm/arch-bcm2835/sdhci.h
@@ -1,17 +1,7 @@
 /*
  * (C) Copyright 2012 Stephen Warren
  *
- * See file CREDITS for list of people who contributed to this
- * project.
- *
- * 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.
+ * SPDX-License-Identifier:	GPL-2.0
  */
 
 #ifndef _BCM2835_SDHCI_H_