sp-cinder: Mention Ubuntu 20.04 in the nodeset name

Change-Id: Ia1827fc15eeb40047fce9b71eeb424ac88346c95
diff --git a/zuul.d/sp-cinder.yaml b/zuul.d/sp-cinder.yaml
index 51dd43d..daa1c55 100644
--- a/zuul.d/sp-cinder.yaml
+++ b/zuul.d/sp-cinder.yaml
@@ -82,7 +82,7 @@
 #        (^(tempest\.((api\..*volume)|scenario\.test_encrypted_cinder_volumes|scenario\.test_volume|scenario\.test_shelve_instance))|(cinder_tempest_plugin))
 
 - nodeset:
-    name: openstack-multi-node-mixed
+    name: ubuntu2004-openstack-multi-node-mixed
     nodes:
       - name: controller
         label: os-ubuntu2004-large
@@ -117,7 +117,7 @@
       # - config
       - sp-osci
     timeout: 10800
-    nodeset: openstack-multi-node-mixed
+    nodeset: ubuntu2004-openstack-multi-node-mixed
     attempts: 1
     secrets:
       # openstack-client
@@ -222,7 +222,7 @@
     required-projects:
       - opendev.org/openstack/tempest
     timeout: 10800
-    nodeset: openstack-multi-node-mixed
+    nodeset: ubuntu2004-openstack-multi-node-mixed
     attempts: 1
     secrets:
       # openstack-client