ide: remove ide_dma_enable()

* check ->speedproc return value in ide_tune_dma()
* use ide_tune_dma() in cmd64x/cs5530/sc1200/siimage/sl82c105/scc_pata drivers
* remove no longer needed ide_dma_enable()

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/pci/cs5530.c b/drivers/ide/pci/cs5530.c
index aacb79b..1eec1f30 100644
--- a/drivers/ide/pci/cs5530.c
+++ b/drivers/ide/pci/cs5530.c
@@ -137,12 +137,8 @@
 
 static int cs5530_config_dma(ide_drive_t *drive)
 {
-	if (ide_use_dma(drive)) {
-		u8 mode = ide_max_dma_mode(drive);
-
-		if (mode && drive->hwif->speedproc(drive, mode) == 0)
-			return 0;
-	}
+	if (ide_tune_dma(drive))
+		return 0;
 
 	return 1;
 }