qemu-doc: Mention host_net_add/-remove in the deprecation chapter

The two HMP commands host_net_add and -remove have recently been
marked as deprecated, too, so we should now mention them in the
chapter of deprecated features.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
1 file changed