ide: merge ide_hwgroup_t with ide_hwif_t (v2)

* Merge ide_hwgroup_t with ide_hwif_t.

* Cleanup init_irq() accordingly, then remove no longer needed
  ide_remove_port_from_hwgroup() and ide_ports[].

* Remove now unused HWGROUP() macro.

While at it:

* ide_dump_ata_error() fixups

v2:
* Fix ->quirk_list check in do_ide_request()
  (s/hwif->cur_dev/prev_port->cur_dev).

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/pdc202xx_old.c b/drivers/ide/pdc202xx_old.c
index 624e62e..072ef70 100644
--- a/drivers/ide/pdc202xx_old.c
+++ b/drivers/ide/pdc202xx_old.c
@@ -169,8 +169,8 @@
 	if (drive->current_speed > XFER_UDMA_2)
 		pdc_old_enable_66MHz_clock(drive->hwif);
 	if (drive->media != ide_disk || (drive->dev_flags & IDE_DFLAG_LBA48)) {
-		struct request *rq	= HWGROUP(drive)->rq;
 		ide_hwif_t *hwif	= HWIF(drive);
+		struct request *rq	= hwif->rq;
 		unsigned long high_16	= hwif->extra_base - 16;
 		unsigned long atapi_reg	= high_16 + (hwif->channel ? 0x24 : 0x20);
 		u32 word_count	= 0;