iommu/mediatek: Allow IOMMU_DOMAIN_UNMANAGED for PCIe VFIO

Allow the type IOMMU_DOMAIN_UNMANAGED since vfio_iommu_type1.c always call
iommu_domain_alloc. The PCIe EP works ok when going through vfio.
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Link: https://lore.kernel.org/r/20220503071427.2285-20-yong.wu@mediatek.comSigned-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/mtk_iommu.c

@@ -446,7 +446,7 @@ static struct iommu_domain *mtk_iommu_domain_alloc(unsigned type)
 {
 	struct mtk_iommu_domain *dom;
 
-	if (type != IOMMU_DOMAIN_DMA)
+	if (type != IOMMU_DOMAIN_DMA && type != IOMMU_DOMAIN_UNMANAGED)
 		return NULL;
 
 	dom = kzalloc(sizeof(*dom), GFP_KERNEL);