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>
diff --git a/drivers/ide/setup-pci.c b/drivers/ide/setup-pci.c
index 1c0c557..b15cad5 100644
--- a/drivers/ide/setup-pci.c
+++ b/drivers/ide/setup-pci.c
@@ -541,7 +541,6 @@
 
 int ide_setup_pci_device(struct pci_dev *dev, const struct ide_port_info *d)
 {
-	struct ide_host *host;
 	hw_regs_t hw[4], *hws[] = { NULL, NULL, NULL, NULL };
 	int ret;
 
@@ -551,9 +550,7 @@
 		/* FIXME: silent failure can happen */
 		ide_pci_setup_ports(dev, d, ret, &hw[0], &hws[0]);
 
-		host = ide_host_alloc(d, hws);
-		if (host)
-			ide_host_register(host, d, hws);
+		ret = ide_host_add(d, hws, NULL);
 	}
 
 	return ret;
@@ -564,7 +561,6 @@
 			  const struct ide_port_info *d)
 {
 	struct pci_dev *pdev[] = { dev1, dev2 };
-	struct ide_host *host;
 	int ret, i;
 	hw_regs_t hw[4], *hws[] = { NULL, NULL, NULL, NULL };
 
@@ -582,9 +578,7 @@
 		ide_pci_setup_ports(pdev[i], d, ret, &hw[i*2], &hws[i*2]);
 	}
 
-	host = ide_host_alloc(d, hws);
-	if (host)
-		ide_host_register(host, d, hws);
+	ret = ide_host_add(d, hws, NULL);
 out:
 	return ret;
 }