DMA-API: amba: get rid of separate dma_mask

AMBA Primecell devices always treat streaming and coherent DMA exactly
the same, so there's no point in having the masks separated.

Acked-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

drivers/of/platform.c

@@ -284,9 +284,6 @@ static struct amba_device *of_amba_device_create(struct device_node *node,
 	else
 		of_device_make_bus_id(&dev->dev);
 
-	/* setup amba-specific device info */
-	dev->dma_mask = ~0;
-
 	/* Allow the HW Peripheral ID to be overridden */
 	prop = of_get_property(node, "arm,primecell-periphid", NULL);
 	if (prop)