ide: add short cables support

This patch allows users to override both host and device side cable detection
with "ideX=ata66" kernel parameter.  Thanks to this it should be now possible
to use UDMA > 2 modes on systems (laptops mainly) which use short 40-pin cable
instead of 80-pin one.

Next patches add automatic detection of some systems using short cables.

Changes:

* Rename hwif->udma_four to hwif->cbl and make it u8.

* Convert all existing users accordingly (use ATA_CBL_* defines while at it).  

* Add ATA_CBL_PATA40_SHORT support to ide-iops.c:eighty_ninty_three().

* Use ATA_CBL_PATA40_SHORT for "ideX=ata66" kernel parameter.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Reviewed-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
diff --git a/drivers/ide/pci/cs5535.c b/drivers/ide/pci/cs5535.c
index 41925c4..10f61f3 100644
--- a/drivers/ide/pci/cs5535.c
+++ b/drivers/ide/pci/cs5535.c
@@ -187,7 +187,8 @@
 
 	/* if a 80 wire cable was detected */
 	pci_read_config_byte(dev, CS5535_CABLE_DETECT, &bit);
-	return (bit & 1);
+
+	return (bit & 1) ? ATA_CBL_PATA80 : ATA_CBL_PATA40;
 }
 
 /****
@@ -212,8 +213,7 @@
 	hwif->ultra_mask = 0x1F;
 	hwif->mwdma_mask = 0x07;
 
-
-	hwif->udma_four = cs5535_cable_detect(hwif->pci_dev);
+	hwif->cbl = cs5535_cable_detect(hwif->pci_dev);
 
 	if (!noautodma)
 		hwif->autodma = 1;