drm/nouveau: teach nouveau_bo_pin() how to force a contig vram allocation

We have the ability to move buffers around in the kernel if necessary,
and should probably use it rather than failing if userspace passes us
a non-contig buffer for a plane.

The NOUVEAU_GEM_TILE_NONCONTIG flag from userspace will become a mere
initial placement hint once all the relevant paths have been updated.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nv50_fence.c

@@ -102,7 +102,7 @@ nv50_fence_create(struct nouveau_drm *drm)
 	ret = nouveau_bo_new(drm->dev, 4096, 0x1000, TTM_PL_FLAG_VRAM,
 			     0, 0x0000, NULL, NULL, &priv->bo);
 	if (!ret) {
-		ret = nouveau_bo_pin(priv->bo, TTM_PL_FLAG_VRAM);
+		ret = nouveau_bo_pin(priv->bo, TTM_PL_FLAG_VRAM, false);
 		if (!ret) {
 			ret = nouveau_bo_map(priv->bo);
 			if (ret)