[ARM] S3C24A0: Remove duplicate <mach/io.h> file

The commit 39263db7986bf15c753f6847699107bdf5a2e318 added
a default <mach/io.h> implementation which is shared if
needed between all the s3c implementations. Remove the
s3c24a0 version which is the same as this.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

arch/arm/mach-s3c24a0/include/mach/io.h

-/* arch/arm/mach-s3c24a0/include/mach/io.h
- *
- * Copyright 2008 Simtec Electronics
- *	Ben Dooks <ben-linux@fluff.org>
- *
- * IO access and mapping routines for the S3C24A0
- */
-
-#ifndef __ASM_ARM_ARCH_IO_H
-#define __ASM_ARM_ARCH_IO_H
-
-/* No current ISA/PCI bus support. */
-#define __io(a)		((void __iomem *)(a))
-#define __mem_pci(a)	(a)
-
-#endif