iommu/virtio: Do not dereference fwnode in struct device

In order to make the underneath API easier to change in the future,
prevent users from dereferencing fwnode from struct device.
Instead, use the specific device_match_fwnode() API for that.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/20220801165142.20898-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/virtio-iommu.c

@@ -925,7 +925,7 @@ static struct virtio_driver virtio_iommu_drv;
 
 static int viommu_match_node(struct device *dev, const void *data)
 {
-	return dev->parent->fwnode == data;
+	return device_match_fwnode(dev->parent, data);
 }
 
 static struct viommu_dev *viommu_get_by_fwnode(struct fwnode_handle *fwnode)