Hexagon: switch to using the device type for IO mappings

#define __HEXAGON_C_WB		0x0	/* Write-back, no L2 */

#define	__HEXAGON_C_WT		0x1	/* Write-through, no L2 */

#define	__HEXAGON_C_UNC		0x6	/* Uncached memory */

#if CONFIG_HEXAGON_ARCH_VERSION >= 2

#define	__HEXAGON_C_DEV		0x4	/* Device register space */

#define	__HEXAGON_C_WT_L2	0x5	/* Write-through, with L2 */

/* this really should be #if CONFIG_HEXAGON_ARCH = 2 but that's not defined */

#if defined(CONFIG_HEXAGON_COMET) || defined(CONFIG_QDSP6_ST1)

#define __HEXAGON_C_UNC		__HEXAGON_C_DEV

#else

#define	__HEXAGON_C_UNC		0x6	/* Uncached memory */

#define __HEXAGON_C_DEV		__HEXAGON_C_UNC

#endif

#define	__HEXAGON_C_WT_L2	0x5	/* Write-through, with L2 */

#define	__HEXAGON_C_WB_L2	0x7	/* Write-back, with L2 */

/*