Fix spelling of 'platform' in comments and doc

Replace platfrom -> platform.

This is a frequent spelling bug.

Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/arch/arm/plat-s3c/include/plat/nand.h b/arch/arm/plat-s3c/include/plat/nand.h
index 226147b..b64115f 100644
--- a/arch/arm/plat-s3c/include/plat/nand.h
+++ b/arch/arm/plat-s3c/include/plat/nand.h
@@ -3,7 +3,7 @@
  * Copyright (c) 2004 Simtec Electronics
  *	Ben Dooks <ben@simtec.co.uk>
  *
- * S3C2410 - NAND device controller platfrom_device info
+ * S3C2410 - NAND device controller platform_device info
  *
  * 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