Rename devstack-plugin-ceph jobs

These jobs are in-repo now and renamed, follow renamed.

Change-Id: I7441efa0e2814e2851409e6ad670f1c7d3f95622
Depends-On: https://review.openstack.org/543048

.zuul.yaml

@@ -42,7 +42,7 @@
               - ^contrib/block-box.*$
               - ^doc/.*$
               - ^releasenotes/.*$
-        - legacy-tempest-dsvm-full-devstack-plugin-ceph:
+        - devstack-plugin-ceph-tempest:
             voting: false
             irrelevant-files:
               - ^(test-|)requirements.txt$
@@ -278,7 +278,7 @@
               - ^setup.cfg$
               - ^tools/.*$
               - ^tox.ini$
-        - legacy-tempest-dsvm-py35-full-devstack-plugin-ceph:
+        - devstack-plugin-ceph-tempest-py3:
             irrelevant-files:
               - ^(test-|)requirements.txt$
               - ^.*\.rst$