drm/msm: set dma_mask properly

Previous value really only made sense on armv7 without LPAE.  Everything
that supports more than 4g of memory also has iommu's that can map
anything.
Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/msm_drv.c

@@ -1038,7 +1038,13 @@ static int msm_pdev_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
+	/* on all devices that I am aware of, iommu's which can map
+	 * any address the cpu can see are used:
+	 */
+	ret = dma_set_mask_and_coherent(&pdev->dev, ~0);
+	if (ret)
+		return ret;
+
 	return component_master_add_with_match(&pdev->dev, &msm_drm_ops, match);
 }