ide: add ide_device_add()

* Add ide_device_add() helper and convert host drivers to use it
  instead of open-coded variants.

* Make ide_pci_setup_ports() and do_ide_setup_pci_device()
  take 'u8 *idx' argument instead of 'ata_index_t *index'.

* Remove no longer needed ata_index_t.

* Unexport probe_hwif_init() and make it static.

* Unexport ide_proc_register_port().

There should be no functionality changes caused by this patch
(sgiioc4.c: ide_proc_register_port() requires hwif->present
 to be set and it won't be set if probe_hwif_init() fails).

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/legacy/dtc2278.c b/drivers/ide/legacy/dtc2278.c
index f165212..12a7182 100644
--- a/drivers/ide/legacy/dtc2278.c
+++ b/drivers/ide/legacy/dtc2278.c
@@ -94,6 +94,7 @@
 {
 	unsigned long flags;
 	ide_hwif_t *hwif, *mate;
+	static u8 idx[4] = { 0, 1, 0xff, 0xff };
 
 	hwif = &ide_hwifs[0];
 	mate = &ide_hwifs[1];
@@ -134,11 +135,7 @@
 	mate->mate = hwif;
 	mate->channel = 1;
 
-	probe_hwif_init(hwif);
-	probe_hwif_init(mate);
-
-	ide_proc_register_port(hwif);
-	ide_proc_register_port(mate);
+	ide_device_add(idx);
 
 	return 0;
 }