drm/etnaviv: only try to use the linear window on MMUv1

As the comment above the code states, the linear window is only
available on MMUv1. Don't try to use it on MMUv2.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

drivers/gpu/drm/etnaviv/etnaviv_mmu.c

@@ -115,7 +115,8 @@ int etnaviv_iommu_map_gem(struct etnaviv_iommu *mmu,
 	mutex_lock(&mmu->lock);
 
 	/* v1 MMU can optimize single entry (contiguous) scatterlists */
-	if (sgt->nents == 1 && !(etnaviv_obj->flags & ETNA_BO_FORCE_MMU)) {
+	if (mmu->version == ETNAVIV_IOMMU_V1 &&
+	    sgt->nents == 1 && !(etnaviv_obj->flags & ETNA_BO_FORCE_MMU)) {
 		u32 iova;
 
 		iova = sg_dma_address(sgt->sgl) - memory_base;