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/ide-taskfile.c b/drivers/ide/ide-taskfile.c
index bf4fb9d..693e8d15 100644
--- a/drivers/ide/ide-taskfile.c
+++ b/drivers/ide/ide-taskfile.c
@@ -361,7 +361,7 @@
 static ide_startstop_t task_in_intr(ide_drive_t *drive)
 {
 	ide_hwif_t *hwif = drive->hwif;
-	struct request *rq = hwif->hwgroup->rq;
+	struct request *rq = hwif->rq;
 	u8 stat = hwif->tp_ops->read_status(hwif);
 
 	/* Error? */
@@ -395,7 +395,7 @@
 static ide_startstop_t task_out_intr (ide_drive_t *drive)
 {
 	ide_hwif_t *hwif = drive->hwif;
-	struct request *rq = HWGROUP(drive)->rq;
+	struct request *rq = hwif->rq;
 	u8 stat = hwif->tp_ops->read_status(hwif);
 
 	if (!OK_STAT(stat, DRIVE_READY, drive->bad_wstat))