ide: remove ->dma_{status,command} fields from ide_hwif_t

* Use ->dma_base + offset instead of ->dma_{status,command}
  and remove no longer needed ->dma_{status,command}.

While at it:

* Use ATA_DMA_* defines.

There should be no functional changes caused by this patch.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/pci/cmd64x.c b/drivers/ide/pci/cmd64x.c
index cfa784b..ce58bfc 100644
--- a/drivers/ide/pci/cmd64x.c
+++ b/drivers/ide/pci/cmd64x.c
@@ -262,7 +262,7 @@
 	unsigned long base	= hwif->dma_base - (hwif->channel * 8);
 	u8 irq_mask		= hwif->channel ? MRDMODE_INTR_CH1 :
 						  MRDMODE_INTR_CH0;
-	u8 dma_stat		= inb(hwif->dma_status);
+	u8 dma_stat		= inb(hwif->dma_base + ATA_DMA_STATUS);
 	u8 mrdmode		= inb(base + 1);
 
 #ifdef DEBUG
@@ -286,7 +286,7 @@
 	int irq_reg		= hwif->channel ? ARTTIM23 : CFR;
 	u8  irq_mask		= hwif->channel ? ARTTIM23_INTR_CH1 :
 						  CFR_INTR_CH0;
-	u8  dma_stat		= inb(hwif->dma_status);
+	u8  dma_stat		= inb(hwif->dma_base + ATA_DMA_STATUS);
 	u8  irq_stat		= 0;
 
 	(void) pci_read_config_byte(dev, irq_reg, &irq_stat);
@@ -317,13 +317,13 @@
 
 	drive->waiting_for_dma = 0;
 	/* get DMA status */
-	dma_stat = inb(hwif->dma_status);
+	dma_stat = inb(hwif->dma_base + ATA_DMA_STATUS);
 	/* read DMA command state */
-	dma_cmd = inb(hwif->dma_command);
+	dma_cmd = inb(hwif->dma_base + ATA_DMA_CMD);
 	/* stop DMA */
-	outb(dma_cmd & ~1, hwif->dma_command);
+	outb(dma_cmd & ~1, hwif->dma_base + ATA_DMA_CMD);
 	/* clear the INTR & ERROR bits */
-	outb(dma_stat | 6, hwif->dma_status);
+	outb(dma_stat | 6, hwif->dma_base + ATA_DMA_STATUS);
 	/* and free any DMA resources */
 	ide_destroy_dmatable(drive);
 	/* verify good DMA status */