iommu/amd: Remove dma_mask check from check_device()

The check was only needed for the DMA-API implementation in the AMD
IOMMU driver, which no longer exists.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Link: https://lore.kernel.org/r/20200429133712.31431-6-joro@8bytes.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/amd_iommu.c

@@ -326,7 +326,7 @@ static bool check_device(struct device *dev)
 {
 	int devid;
 
-	if (!dev || !dev->dma_mask)
+	if (!dev)
 		return false;
 
 	devid = get_device_id(dev);