media: iommu/mediatek: Return ENODEV if the device is NULL

The platform device is created at:
of_platform_default_populate_init:  arch_initcall_sync
  ->of_platform_populate
        ->of_platform_device_create_pdata

When entering our probe, all the devices should be already created.
if it is null, means NODEV. Currently we don't get the fail case.
It's a minor fix, no need add fixes tags.
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Acked-by: Joerg Roedel <jroedel@suse.de>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

drivers/iommu/mtk_iommu.c

@@ -848,7 +848,7 @@ static int mtk_iommu_probe(struct platform_device *pdev)
 		plarbdev = of_find_device_by_node(larbnode);
 		if (!plarbdev) {
 			of_node_put(larbnode);
-			return -EPROBE_DEFER;
+			return -ENODEV;
 		}
 		data->larb_imu[id].dev = &plarbdev->dev;
 

drivers/iommu/mtk_iommu_v1.c

@@ -604,7 +604,7 @@ static int mtk_iommu_probe(struct platform_device *pdev)
 		plarbdev = of_find_device_by_node(larbnode);
 		if (!plarbdev) {
 			of_node_put(larbnode);
-			return -EPROBE_DEFER;
+			return -ENODEV;
 		}
 		data->larb_imu[i].dev = &plarbdev->dev;