ide: remove [ata_]select_t

* Use 'drive->dn & 1' in ide_init_disk().

* remove [ata_]select_t.

While at it:

* Use ATA_DEVICE_OBS define in ide_port_init_devices_data().

Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/legacy/ide-4drives.c b/drivers/ide/legacy/ide-4drives.c
index c76d55d..9e85b1e 100644
--- a/drivers/ide/legacy/ide-4drives.c
+++ b/drivers/ide/legacy/ide-4drives.c
@@ -14,7 +14,7 @@
 static void ide_4drives_init_dev(ide_drive_t *drive)
 {
 	if (drive->hwif->channel)
-		drive->select.all ^= 0x20;
+		drive->select ^= 0x20;
 }
 
 static const struct ide_port_ops ide_4drives_port_ops = {