schemas: Extract overrides for the domain element from 'domain.rng'

Move the overrides into a single file so that later patches can add
another top level element 'inactiveDomain' used in snapshots.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

src/conf/schemas/domain.rng

@@ -6,16 +6,6 @@
     <ref name="domain"/>
   </start>
 
-  <include href="domaincommon.rng"/>
-
-  <define name="storageStartupPolicy" combine="choice">
-    <!-- overrides the no-op version in storagecommon.rng -->
-    <ref name="startupPolicy"/>
-  </define>
-
-  <define name="storageSourceExtra" combine="choice">
-    <!-- overrides the no-op version in storagecommon.rng -->
-    <ref name="diskspec"/>
-  </define>
+  <include href="domainoverrides.rng"/>
 
 </grammar>

src/conf/schemas/domainoverrides.rng

@@ -0,0 +1,16 @@
+<?xml version="1.0"?>
+<grammar xmlns="http://relaxng.org/ns/structure/1.0" datatypeLibrary="http://www.w3.org/2001/XMLSchema-datatypes">
+  <!-- Overrides for the no-op versions of storage elements for use with domain XMLs. -->
+  <include href="domaincommon.rng"/>
+
+  <define name="storageStartupPolicy" combine="choice">
+    <!-- overrides the no-op version in storagecommon.rng -->
+    <ref name="startupPolicy"/>
+  </define>
+
+  <define name="storageSourceExtra" combine="choice">
+    <!-- overrides the no-op version in storagecommon.rng -->
+    <ref name="diskspec"/>
+  </define>
+
+</grammar>

src/conf/schemas/meson.build

@@ -8,6 +8,7 @@ schema_files = [
   'domaincheckpoint.rng',
   'domaincommon.rng',
   'domain.rng',
+  'domainoverrides.rng',
   'domainsnapshot.rng',
   'interface.rng',
   'networkcommon.rng',