docs: bhyve: document autoport support

- Update the driver page with the information about using
   autport for VNC ports
 - Add a news entry

Signed-off-by: Roman Bogorodskiy <bogorodskiy@gmail.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

docs/drvbhyve.html.in

@@ -381,6 +381,14 @@ will be used. Please refer to the
 manual page and the <a href="https://wiki.freebsd.org/bhyve">bhyve wiki</a> for more details on using
 the <code>vgaconf</code> option.</p>
 
+<p><span class="since">Since 3.7.0</span>, it's possible to use <code>autoport</code>
+to let libvirt allocate VNC port automatically (instead of explicitly specifying
+it with the <code>port</code> attribute):</p>
+
+<pre>
+    &lt;graphics type='vnc' autoport='yes'&gt;
+</pre>
+
 <h3><a id="clockconfig">Clock configuration</a></h3>
 
 <p>Originally bhyve supported only localtime for RTC. Support for UTC time was introduced in

docs/news.xml

@@ -35,6 +35,16 @@
 <libvirt>
   <release version="v3.7.0" date="unreleased">
     <section title="New features">
+      <change>
+        <summary>
+          bhyve: Support autoport for VNC ports
+        </summary>
+        <description>
+          It's no longer necessary to explicitly specify VNC port for the bhyve
+          guests. With the autoport feature it will be allocated automatically.
+          Please refer to the bhyve driver documentation for examples.
+        </description>
+      </change>
     </section>
     <section title="Improvements">
     </section>