ARM: s3c24xx: Avoid warning for inb/outb

s3c24xx implements its own inb/outb macros, but the implementation
prints warnings when the port number argument is not a 32-bit scalar:

drivers/scsi/pas16.c: In function 'NCR5380_pwrite':
arch/arm/mach-s3c24xx/include/mach/io.h:193:68: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
 #define __ioaddrc(port) ((__PORT_PCIO(port) ? PCIO_BASE + (port) : (void __iomem *)(port)))

This slightly modifies the definition of the __ioaddrc macro to avoid
the warning.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>