Add compute tags to tempest/api/database/flavors test

Partially implements bp add-service-tags

Change-Id: Idfe3f86cfdb529340e5e290dd5dc8e9b549f7f5b
diff --git a/tempest/api/database/flavors/test_flavors.py b/tempest/api/database/flavors/test_flavors.py
index 64d71b9..7d30f26 100644
--- a/tempest/api/database/flavors/test_flavors.py
+++ b/tempest/api/database/flavors/test_flavors.py
@@ -55,6 +55,7 @@
                 self.assertNotIn(name, db_flavor)
 
     @test.attr(type='smoke')
+    @test.services('compute')
     def test_compare_db_flavors_with_os(self):
         resp, db_flavors = self.client.list_db_flavors()
         self.assertEqual(200, resp.status)