drm/nouveau/nvif: simplify and tidy library interfaces

A variety of tweaks to the NVIF library interfaces, mostly ripping out
things that turned out to be not so useful.

- Removed refcounting from nvif_object, callers are expected to not be
  stupid instead.
- nvif_client is directly reachable from anything derived from nvif_object,
  removing the need for heuristics to locate it
- _new() versions of interfaces, that allocate memory for the object
  they construct, have been removed.  The vast majority of callers used
  the embedded _init() interfaces.
- No longer storing constructor arguments (and the data returned from
  nvkm) inside nvif_object, it's more or less unused and just wastes
  memory.

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

drivers/gpu/drm/nouveau/nouveau_fence.c

@@ -169,7 +169,7 @@ void
 nouveau_fence_context_new(struct nouveau_channel *chan, struct nouveau_fence_chan *fctx)
 {
 	struct nouveau_fence_priv *priv = (void*)chan->drm->fence;
-	struct nouveau_cli *cli = (void *)nvif_client(chan->object);
+	struct nouveau_cli *cli = (void *)chan->user.client;
 	int ret;
 
 	INIT_LIST_HEAD(&fctx->flip);
@@ -188,13 +188,12 @@ nouveau_fence_context_new(struct nouveau_channel *chan, struct nouveau_fence_cha
 	if (!priv->uevent)
 		return;
 
-	ret = nvif_notify_init(chan->object, NULL,
-			 nouveau_fence_wait_uevent_handler, false,
-			 G82_CHANNEL_DMA_V0_NTFY_UEVENT,
-			 &(struct nvif_notify_uevent_req) { },
-			 sizeof(struct nvif_notify_uevent_req),
-			 sizeof(struct nvif_notify_uevent_rep),
-			 &fctx->notify);
+	ret = nvif_notify_init(&chan->user, nouveau_fence_wait_uevent_handler,
+			       false, G82_CHANNEL_DMA_V0_NTFY_UEVENT,
+			       &(struct nvif_notify_uevent_req) { },
+			       sizeof(struct nvif_notify_uevent_req),
+			       sizeof(struct nvif_notify_uevent_rep),
+			       &fctx->notify);
 
 	WARN_ON(ret);
 }