ide: make drive->id an union (take 2)

Make drive->id an unnamed union so id can be accessed either by using
'u16 *id' or 'struct hd_driveid *driveid'.  Then convert all existing
drive->id users accordingly (using 'u16 *id' when possible).

This is an intermediate step to make ide 'struct hd_driveid'-free.

While at it:

- Add missing KERN_CONTs in it821x.c.

- Use ATA_ID_WORDS and ATA_ID_*_LEN defines.

- Remove unnecessary checks for drive->id.

- s/drive_table/table/ in ide_in_drive_list().

- Cleanup ide_config_drive_speed() a bit.

- s/drive1/dev1/ & s/drive0/dev0/ in ide_undecoded_slave().

v2:
Fix typo in drivers/ide/ppc/pmac.c. (From Stephen Rothwell)

There should be no functional changes caused by this patch.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/scsi/ide-scsi.c b/drivers/scsi/ide-scsi.c
index 81c16cb..b1b506f 100644
--- a/drivers/scsi/ide-scsi.c
+++ b/drivers/scsi/ide-scsi.c
@@ -452,7 +452,7 @@
  */
 static void idescsi_setup (ide_drive_t *drive, idescsi_scsi_t *scsi)
 {
-	if (drive->id && (drive->id->config & 0x0060) == 0x20)
+	if ((drive->id[ATA_ID_CONFIG] & 0x0060) == 0x20)
 		set_bit(IDE_AFLAG_DRQ_INTERRUPT, &drive->atapi_flags);
 	clear_bit(IDESCSI_SG_TRANSFORM, &scsi->transform);
 #if IDESCSI_DEBUG_LOG
@@ -811,6 +811,7 @@
 	struct gendisk *g;
 	static int warned;
 	int err = -ENOMEM;
+	u16 last_lun;
 
 	if (!warned && drive->media == ide_cdrom) {
 		printk(KERN_WARNING "ide-scsi is deprecated for cd burning! Use ide-cd and give dev=/dev/hdX as device\n");
@@ -836,12 +837,12 @@
 
 	host->max_id = 1;
 
-	if (drive->id->last_lun)
-		debug_log("%s: id->last_lun=%u\n", drive->name,
-			  drive->id->last_lun);
+	last_lun = drive->id[ATA_ID_LAST_LUN];
+	if (last_lun)
+		debug_log("%s: last_lun=%u\n", drive->name, last_lun);
 
-	if ((drive->id->last_lun & 0x7) != 7)
-		host->max_lun = (drive->id->last_lun & 0x7) + 1;
+	if ((last_lun & 7) != 7)
+		host->max_lun = (last_lun & 7) + 1;
 	else
 		host->max_lun = 1;