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/au1xxx-ide.c b/drivers/ide/au1xxx-ide.c
index 0ec8fd1..db412bc 100644
--- a/drivers/ide/au1xxx-ide.c
+++ b/drivers/ide/au1xxx-ide.c
@@ -213,7 +213,7 @@
 {
 	int i, iswrite, count = 0;
 	ide_hwif_t *hwif = HWIF(drive);
-	struct request *rq = HWGROUP(drive)->rq;
+	struct request *rq = hwif->rq;
 	_auide_hwif *ahwif = &auide_hwif;
 	struct scatterlist *sg;
 
@@ -309,8 +309,8 @@
 }
 
 static int auide_dma_setup(ide_drive_t *drive)
-{       	
-	struct request *rq = HWGROUP(drive)->rq;
+{
+	struct request *rq = drive->hwif->rq;
 
 	if (!auide_build_dmatable(drive)) {
 		ide_map_sg(drive, rq);