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/legacy/q40ide.c b/drivers/ide/legacy/q40ide.c
index 8fb4438..4abd8fc 100644
--- a/drivers/ide/legacy/q40ide.c
+++ b/drivers/ide/legacy/q40ide.c
@@ -131,7 +131,6 @@
 
 static int __init q40ide_init(void)
 {
-    struct ide_host *host;
     int i;
     hw_regs_t hw[Q40IDE_NUM_HWIFS], *hws[] = { NULL, NULL, NULL, NULL };
 
@@ -160,11 +159,7 @@
 	hws[i] = &hw[i];
     }
 
-    host = ide_host_alloc(&q40ide_port_info, hws);
-    if (host)
-	ide_host_register(host, &q40ide_port_info, hws);
-
-    return 0;
+    return ide_host_add(&q40ide_port_info, hws, NULL);
 }
 
 module_init(q40ide_init);