ide: constify struct ide_dma_ops

* Export ide_dma_exec_cmd() and __ide_dma_test_irq().

* Constify struct ide_dma_ops.

* Always set hwif->dma_ops to &sff_dma_ops in ide_setup_dma()
  (it is later overriden by ide_init_port() if needed) and drop
  'const struct ide_port_info *d' argument.

While at it:

* Rename __ide_dma_test_irq() to ide_dma_test_irq().

Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/setup-pci.c b/drivers/ide/setup-pci.c
index 9a1e01e..5171601 100644
--- a/drivers/ide/setup-pci.c
+++ b/drivers/ide/setup-pci.c
@@ -385,7 +385,7 @@
 		if (ide_allocate_dma_engine(hwif))
 			return -1;
 
-		ide_setup_dma(hwif, base, d);
+		ide_setup_dma(hwif, base);
 	}
 
 	return 0;