ide: add ide_deprecated_find_port() helper

* Factor out code for finding ide_hwifs[] slot from ide_register_hw()
  to ide_deprecated_find_port().

* Convert bast-ide, ide-cs and delkin_cb host drivers to use ide_device_add()
  instead of ide_register_hw() (while at it drop doing "ide_unregister()" loop
  which tries to unregister _all_ IDE interfaces if useable ide_hwifs[] slot
  cannot be find).

This patch leaves us with only two ide_register_hw() users:
- drivers/macintosh/mediabay.c
- drivers/ide/ide.c

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/legacy/ide-cs.c b/drivers/ide/legacy/ide-cs.c
index 2d772e2..38e87ad 100644
--- a/drivers/ide/legacy/ide-cs.c
+++ b/drivers/ide/legacy/ide-cs.c
@@ -145,13 +145,36 @@
 
 static int idecs_register(unsigned long io, unsigned long ctl, unsigned long irq, struct pcmcia_device *handle)
 {
+    ide_hwif_t *hwif;
     hw_regs_t hw;
+    int i;
+    u8 idx[4] = { 0xff, 0xff, 0xff, 0xff };
+
     memset(&hw, 0, sizeof(hw));
     ide_init_hwif_ports(&hw, io, ctl, NULL);
     hw.irq = irq;
     hw.chipset = ide_pci;
     hw.dev = &handle->dev;
-    return ide_register_hw(&hw, &ide_undecoded_slave, NULL);
+
+    hwif = ide_deprecated_find_port(hw.io_ports[IDE_DATA_OFFSET]);
+    if (hwif == NULL)
+	return -1;
+
+    i = hwif->index;
+
+    if (hwif->present)
+	ide_unregister(i, 0, 1);
+    else if (!hwif->hold)
+	ide_init_port_data(hwif, i);
+
+    ide_init_port_hw(hwif, &hw);
+    hwif->quirkproc = &ide_undecoded_slave;
+
+    idx[0] = i;
+
+    ide_device_add(idx, NULL);
+
+    return hwif->present ? i : -1;
 }
 
 /*======================================================================