ide: add struct ide_port_ops (take 2)

* Move hooks for port/host specific methods from ide_hwif_t to
  'struct ide_port_ops'.

* Add 'const struct ide_port_ops *port_ops' to 'struct ide_port_info'
  and ide_hwif_t.

* Update host drivers and core code accordingly.

While at it:

* Rename ata66_*() cable detect functions to *_cable_detect() to match
  the standard naming. (Suggested by Sergei Shtylyov)

v2:
* Fix build for bast-ide. (Noticed by Andrew Morton)

Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ide.c b/drivers/ide/ide.c
index d868ca4..91a3c8a 100644
--- a/drivers/ide/ide.c
+++ b/drivers/ide/ide.c
@@ -585,11 +585,12 @@
 {
 	struct request rq;
 	ide_hwif_t *hwif = drive->hwif;
+	const struct ide_port_ops *port_ops = hwif->port_ops;
 
 	if (arg < 0 || arg > 255)
 		return -EINVAL;
 
-	if (hwif->set_pio_mode == NULL ||
+	if (port_ops == NULL || port_ops->set_pio_mode == NULL ||
 	    (hwif->host_flags & IDE_HFLAG_NO_SET_MODE))
 		return -ENOSYS;