drm/msm: remove fence_cbs

This was only used for atomic commit these days.  So instead just give
atomic it's own work-queue where we can do a block on each bo in turn.
Simplifies things a whole bunch and makes the 'struct fence' conversion
easier.

Signed-off-by: Rob Clark <robdclark@gmail.com>
diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 2b859f3..7457939 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -213,6 +213,9 @@
 	flush_workqueue(priv->wq);
 	destroy_workqueue(priv->wq);
 
+	flush_workqueue(priv->atomic_wq);
+	destroy_workqueue(priv->atomic_wq);
+
 	if (kms) {
 		pm_runtime_disable(dev->dev);
 		kms->funcs->destroy(kms);
@@ -339,6 +342,7 @@
 	dev->dev_private = priv;
 
 	priv->wq = alloc_ordered_workqueue("msm", 0);
+	priv->atomic_wq = alloc_ordered_workqueue("msm:atomic", 0);
 	init_waitqueue_head(&priv->pending_crtcs_event);
 
 	INIT_LIST_HEAD(&priv->inactive_list);