ide: add ide_host_add() helper

Add ide_host_add() helper which does ide_host_alloc()+ide_host_register(),
then convert ide_setup_pci_device[s](), ide_legacy_device_add() and some
host drivers to use it.

While at it:

* Fix ide_setup_pci_device[s](), ide_arm.c, gayle.c, ide-4drives.c,
  macide.c, q40ide.c, cmd640.c and cs5520.c to return correct error value.

* -ENOENT -> -ENOMEM in rapide.c, ide-h8300.c, ide-generic.c, au1xxx-ide.c
  and pmac.c

* -ENODEV -> -ENOMEM in palm_bk3710.c, ide_platform.c and delkin_cb.c

* -1 -> -ENOMEM in ide-pnp.c

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

drivers/ide/ide-pnp.c

@@ -31,6 +31,7 @@ static int idepnp_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)
 {
 	struct ide_host *host;
 	unsigned long base, ctl;
+	int rc;
 	hw_regs_t hw, *hws[] = { &hw, NULL, NULL, NULL };
 
 	printk(KERN_INFO DRV_NAME ": generic PnP IDE interface\n");
@@ -59,19 +60,18 @@ static int idepnp_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)
 	hw.irq = pnp_irq(dev, 0);
 	hw.chipset = ide_generic;
 
-	host = ide_host_alloc(NULL, hws);
-	if (host) {
-		pnp_set_drvdata(dev, host);
+	rc = ide_host_add(NULL, hws, &host);
+	if (rc)
+		goto out;
 
-		ide_host_register(host, NULL, hws);
-
-		return 0;
-	}
+	pnp_set_drvdata(dev, host);
 
+	return 0;
+out:
 	release_region(ctl, 1);
 	release_region(base, 8);
 
-	return -1;
+	return rc;
 }
 
 static void idepnp_remove(struct pnp_dev *dev)