ide: add ->read_status method

* Remove ide_read_status() inline helper.

* Add ->read_status method for reading ATA Status register
  and use it instead of ->INB.

While at it:

* Don't use HWGROUP() macro.

There should be no functional changes caused by this patch.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ide-dma.c b/drivers/ide/ide-dma.c
index ac342eb..ecf60db 100644
--- a/drivers/ide/ide-dma.c
+++ b/drivers/ide/ide-dma.c
@@ -100,10 +100,11 @@
  
 ide_startstop_t ide_dma_intr (ide_drive_t *drive)
 {
+	ide_hwif_t *hwif = drive->hwif;
 	u8 stat = 0, dma_stat = 0;
 
-	dma_stat = drive->hwif->dma_ops->dma_end(drive);
-	stat = ide_read_status(drive);
+	dma_stat = hwif->dma_ops->dma_end(drive);
+	stat = hwif->read_status(hwif);
 
 	if (OK_STAT(stat,DRIVE_READY,drive->bad_wstat|DRQ_STAT)) {
 		if (!dma_stat) {