nouveau: offload fence uevents work to workqueue

commit 39126abc upstream.

This should break the deadlock between the fctx lock and the irq lock.

This offloads the processing off the work from the irq into a workqueue.

Cc: linux-stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/576237/


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>