trace: move util/qemu-coroutine*.c trace points into correct file

trace: move util/qemu-coroutine*.c trace points into correct file

The trace points for util/qemu-coroutine*.c were mistakenly left
in the top level trace-events file, instead of util/trace-events
in

  commit 492bb2dd651e780c0723580880acbedb5661e5ad
  Author: Daniel P. Berrange <berrange@redhat.com>
  Date:   Thu Jun 16 09:39:48 2016 +0100

    trace: split out trace events for util/ directory

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1473872624-23285-3-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>