[ARM] dma: constify dma controller name and dma ops

	void 	(*disable)(unsigned int, dma_t *);		/* mandatory */

	int	(*residue)(unsigned int, dma_t *);		/* optional */

	int	(*setspeed)(unsigned int, dma_t *, int);	/* optional */

	char	*type;

	const char *type;

};

struct dma_struct {

	unsigned int	lock;		/* Device is allocated		*/

	const char	*device_id;	/* Device name			*/

	struct dma_ops	*d_ops;

	const struct dma_ops *d_ops;

};

struct floppy_dma {