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-dma-sff.c b/drivers/ide/ide-dma-sff.c
index f6d2d44..623a82d 100644
--- a/drivers/ide/ide-dma-sff.c
+++ b/drivers/ide/ide-dma-sff.c
@@ -175,7 +175,7 @@
 int ide_dma_setup(ide_drive_t *drive)
 {
 	ide_hwif_t *hwif = drive->hwif;
-	struct request *rq = hwif->hwgroup->rq;
+	struct request *rq = hwif->rq;
 	unsigned int reading = rq_data_dir(rq) ? 0 : ATA_DMA_WR;
 	u8 mmio = (hwif->host_flags & IDE_HFLAG_MMIO) ? 1 : 0;
 	u8 dma_stat;
@@ -240,7 +240,7 @@
 	if ((dma_stat & 0x18) == 0x18)	/* BUSY Stupid Early Timer !! */
 		return WAIT_CMD;
 
-	hwif->hwgroup->expiry = NULL;	/* one free ride for now */
+	hwif->expiry = NULL;	/* one free ride for now */
 
 	if (dma_stat & ATA_DMA_ERR)	/* ERROR */
 		return -1;