ide: add struct ide_io_ports (take 3)

* Add struct ide_io_ports and use it instead of `unsigned long io_ports[]`
  in ide_hwif_t.

* Rename io_ports[] in hw_regs_t to io_ports_array[].

* Use un-named union for 'unsigned long io_ports_array[]' and 'struct
  ide_io_ports io_ports' in hw_regs_t.

* Remove IDE_*_OFFSET defines.

v2:
* scc_pata.c build fix from Stephen Rothwell.

v3:
* Fix ctl_adrr typo in Sparc-specific part of ns87415.c.
  (Noticed by Andrew Morton)

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/pci/opti621.c b/drivers/ide/pci/opti621.c
index 684160d..6e99080 100644
--- a/drivers/ide/pci/opti621.c
+++ b/drivers/ide/pci/opti621.c
@@ -279,7 +279,7 @@
 
 	spin_lock_irqsave(&opti621_lock, flags);
 
-	reg_base = hwif->io_ports[IDE_DATA_OFFSET];
+	reg_base = hwif->io_ports.data_addr;
 
 	/* allow Register-B */
 	outb(0xc0, reg_base + CNTRL_REG);