[PATCH] merge sd.h into sd.c and some cleanup

Now that only sd.c includes sd.h it can be safely merged into it.
Also get rid of typedef abuse in sd.c

drivers/scsi/sd.h

-/*
- *    sd.h Copyright (C) 1992 Drew Eckhardt 
- *      SCSI disk driver header file by
- *              Drew Eckhardt 
- *
- *      <drew@colorado.edu>
- *
- *       Modified by Eric Youngdale eric@andante.org to
- *       add scatter-gather, multiple outstanding request, and other
- *       enhancements.
- */
-#ifndef _SD_H
-#define _SD_H
-
-#ifndef _SCSI_H
-#include "scsi.h"
-#endif
-
-#ifndef _GENDISK_H
-#include <linux/genhd.h>
-#endif
-
-typedef struct scsi_disk {
-	sector_t capacity;		/* size in 512-byte sectors */
-	Scsi_Device *device;
-	unsigned char media_present;
-	unsigned char write_prot;
-	unsigned WCE:1;         /* state of disk WCE bit */
-	unsigned RCD:1;         /* state of disk RCD bit */
-} Scsi_Disk;
-
-extern int revalidate_scsidisk(kdev_t dev, int maxusage);
-
-/*
- * Used by pmac to find the device associated with a target.
- */
-extern kdev_t sd_find_target(void *host, int tgt);
-
-#define N_SD_MAJORS	8
-
-#define SD_MAJOR_MASK	(N_SD_MAJORS - 1)
-
-#endif