Hexagon: add IOMEM and _relaxed IO macros

#define IO_SPACE_LIMIT 0xffff

#define _IO_BASE ((void __iomem *)0xfe000000)

#define IOMEM(x)        ((void __force __iomem *)(x))

extern int remap_area_pages(unsigned long start, unsigned long phys_addr,

				unsigned long end, unsigned long flags);

#define __raw_readw readw

#define __raw_readl readl

/*

 * http://comments.gmane.org/gmane.linux.ports.arm.kernel/117626

 */

#define readb_relaxed __raw_readb

#define readw_relaxed __raw_readw

#define readl_relaxed __raw_readl

#define writeb_relaxed __raw_writeb

#define writew_relaxed __raw_writew

#define writel_relaxed __raw_writel

/*

 * Need an mtype somewhere in here, for cache type deals?

 * This is probably too long for an inline.