ACPI/IORT: Set bus DMA mask as appropriate

When an explicit DMA limit is described by firmware, we need to remember
it regardless of how drivers might subsequently update their devices'
masks. The new bus_dma_mask field does that.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/acpi/arm64/iort.c

@@ -1014,6 +1014,7 @@ void iort_dma_setup(struct device *dev, u64 *dma_addr, u64 *dma_size)
 		 * Limit coherent and dma mask based on size
 		 * retrieved from firmware.
 		 */
+		dev->bus_dma_mask = mask;
 		dev->coherent_dma_mask = mask;
 		*dev->dma_mask = mask;
 	}