virt-xml-validate: Add schema for nwfilterbinding

https://bugzilla.redhat.com/show_bug.cgi?id=1600330

Add nwfilterbinding schema in virt-xml-validate for autoprobing.
Add document of nwfilterbinding schema in tools/virt-xml-validate.pod.
Signed-off-by: NHan Han <hhan@redhat.com>
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>

tools/virt-xml-validate.in

@@ -77,6 +77,9 @@ if [ -z "$TYPE" ]; then
      *device*)
         TYPE="nodedev"
         ;;
+     *filterbinding*)
+        TYPE="nwfilterbinding"
+        ;;
      *filter*)
         TYPE="nwfilter"
         ;;

tools/virt-xml-validate.pod

@@ -52,6 +52,10 @@ The schema for the XML format used to declare driver capabilities
 
 The schema for the XML format used by network traffic filters
 
+=item C<nwfilterbinding>
+
+The schema for XML format used by network filter bindings.
+
 =item C<secret>
 
 The schema for the XML format used by secrets descriptions