ide: add struct ide_host (take 3)

* Add struct ide_host which keeps pointers to host's ports.

* Add ide_host_alloc[_all]() and ide_host_remove() helpers.

* Pass 'struct ide_host *host' instead of 'u8 *idx' to
  ide_device_add[_all]() and rename it to ide_host_register[_all]().

* Convert host drivers and core code to use struct ide_host.

* Remove no longer needed ide_find_port().

* Make ide_find_port_slot() static.

* Unexport ide_unregister().

v2:
* Add missing 'struct ide_host *host' to macide.c.

v3:
* Fix build problem in pmac.c (s/ide_alloc_host/ide_host_alloc/)
  (Noticed by Stephen Rothwell).

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/mips/swarm.c b/drivers/ide/mips/swarm.c
index c1ffb83..b12d9d2 100644
--- a/drivers/ide/mips/swarm.c
+++ b/drivers/ide/mips/swarm.c
@@ -72,12 +72,11 @@
  */
 static int __devinit swarm_ide_probe(struct device *dev)
 {
-	ide_hwif_t *hwif;
 	u8 __iomem *base;
+	struct ide_host *host;
 	phys_t offset, size;
 	int i;
 	hw_regs_t hw, *hws[] = { &hw, NULL, NULL, NULL };
-	u8 idx[] = { 0xff, 0xff, 0xff, 0xff };
 
 	if (!SIBYTE_HAVE_IDE)
 		return -ENODEV;
@@ -116,15 +115,13 @@
 	hw.irq = K_INT_GB_IDE;
 	hw.chipset = ide_generic;
 
-	hwif = ide_find_port_slot(&swarm_port_info);
-	if (hwif == NULL)
+	host = ide_host_alloc(&swarm_port_info, hws);
+	if (host == NULL)
 		goto err;
 
-	idx[0] = hwif->index;
+	ide_host_register(host, &swarm_port_info, hws);
 
-	ide_device_add(idx, &swarm_port_info, hws);
-
-	dev_set_drvdata(dev, hwif);
+	dev_set_drvdata(dev, host);
 
 	return 0;
 err: