gpu: host1x: Set DMA mask

The default DMA mask covers a 32 bits address range, but host1x devices
can address a larger range on TK1 and TX1. Set the DMA mask to the range
addressable when we use the IOMMU to prevent the use of bounce buffers.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/drivers/gpu/host1x/dev.h b/drivers/gpu/host1x/dev.h
index 0b6e8e9..dace124 100644
--- a/drivers/gpu/host1x/dev.h
+++ b/drivers/gpu/host1x/dev.h
@@ -96,6 +96,7 @@
 	int	nb_mlocks;		/* host1x: number of mlocks */
 	int	(*init)(struct host1x *); /* initialize per SoC ops */
 	int	sync_offset;
+	u64	dma_mask;		/* mask of addressable memory */
 };
 
 struct host1x {