nodedev: Revert auto-start property for mdevs

We supported autostart of node devices via an xml element, but this
is not consistent with other libvirt objects which use an explicit API
for setting autostart status. So revert this and implement it as an
official API in a future commit.

The initial support was refactored after merging, so this commit reverts
both of those previous commits.

Revert "virNodeDevCapMdevParseXML: Use virXMLPropEnum() for ./start/@type"
This reverts commit 9d4cd1d1cd.

Revert "nodedev: support auto-start property for mdevs"
This reverts commit 42a5585499.

Signed-off-by: Jonathon Jongsma <jjongsma@redhat.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

docs/formatnode.html.in

@@ -388,16 +388,6 @@
               <dd>
                 This element represents the UUID of the mediated device.
               </dd>
-              <dt><code>start</code></dt>
-              <dd>
-                This element represents the start policy for the device.  It
-                has a required attribute <code>type</code>, which can have a
-                value of <code>auto</code> or <code>manual</code>. Mediated
-                devices with an <code>auto</code> start type will be started
-                automatically by the host when the parent device becomes
-                available (either on boot, or when the parent device is
-                attached). Otherwise the device must be started manually.
-              </dd>
             </dl>
           </dd>
           <dt><code>ccw</code></dt>

docs/schemas/nodedev.rng

@@ -622,17 +622,6 @@
           </attribute>
         </element>
       </optional>
-      <optional>
-        <element name="start">
-          <attribute name="type">
-            <choice>
-              <value>manual</value>
-              <value>auto</value>
-            </choice>
-          </attribute>
-          <empty/>
-        </element>
-      </optional>
       <optional>
         <element name="uuid">
           <ref name="UUID"/>