dma: Transfer dma_ops should use DMA address types

DMA operations should function on DMA addresses, not virtual addresses.
Although these are usually the same in U-Boot, it is more correct
to be explicit with our types here.

Signed-off-by: Andrew Davis <afd@ti.com>
diff --git a/drivers/dma/sandbox-dma-test.c b/drivers/dma/sandbox-dma-test.c
index aebf3ee..2b8259a 100644
--- a/drivers/dma/sandbox-dma-test.c
+++ b/drivers/dma/sandbox-dma-test.c
@@ -39,9 +39,9 @@
 };
 
 static int sandbox_dma_transfer(struct udevice *dev, int direction,
-				void *dst, void *src, size_t len)
+				dma_addr_t dst, dma_addr_t src, size_t len)
 {
-	memcpy(dst, src, len);
+	memcpy((void *)dst, (void *)src, len);
 
 	return 0;
 }