ide: remove drive->ctl

Remove drive->ctl (it is always equal to 0x08 after init time).

While at it:

* Use ATA_DEVCTL_OBS define.

There should be no functional changes caused by this patch.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/pci/scc_pata.c b/drivers/ide/pci/scc_pata.c
index 32eb087..1584ebb 100644
--- a/drivers/ide/pci/scc_pata.c
+++ b/drivers/ide/pci/scc_pata.c
@@ -703,7 +703,7 @@
 	}
 
 	/* be sure we're looking at the low order bits */
-	scc_ide_outb(drive->ctl & ~0x80, io_ports->ctl_addr);
+	scc_ide_outb(ATA_DEVCTL_OBS & ~0x80, io_ports->ctl_addr);
 
 	if (task->tf_flags & IDE_TFLAG_IN_NSECT)
 		tf->nsect  = scc_ide_inb(io_ports->nsect_addr);
@@ -717,7 +717,7 @@
 		tf->device = scc_ide_inb(io_ports->device_addr);
 
 	if (task->tf_flags & IDE_TFLAG_LBA48) {
-		scc_ide_outb(drive->ctl | 0x80, io_ports->ctl_addr);
+		scc_ide_outb(ATA_DEVCTL_OBS | 0x80, io_ports->ctl_addr);
 
 		if (task->tf_flags & IDE_TFLAG_IN_HOB_FEATURE)
 			tf->hob_feature = scc_ide_inb(io_ports->feature_addr);