Make grenade jobs voting again

This reverts the changes made to the zuul config in [0]. Since the
backports to the stable branches have been merged, the jobs can be
voting again.

[0] I5d8aa0e58e0409c54451b51de5eb70ba9a68d849

Change-Id: I3f5972e05faea8f11d7e87f3f8b05e4979e6c328

Author: jharbott

.zuul.yaml

@@ -705,12 +705,10 @@
             voting: false
             irrelevant-files: *dsvm-irrelevant-files
         - grenade:
-            voting: false
             irrelevant-files:
               - ^.*\.rst$
               - ^doc/.*$
         - neutron-grenade-multinode:
-            voting: false
             irrelevant-files:
               - ^.*\.rst$
               - ^doc/.*$
@@ -752,18 +750,18 @@
         - devstack-multinode
         - devstack-unit-tests
         - openstack-tox-bashate
-        # - neutron-grenade-multinode:
-        #     irrelevant-files:
-        #       - ^.*\.rst$
-        #       - ^doc/.*$
+        - neutron-grenade-multinode:
+            irrelevant-files:
+              - ^.*\.rst$
+              - ^doc/.*$
         - neutron-tempest-linuxbridge:
             irrelevant-files:
               - ^.*\.rst$
               - ^doc/.*$
-        # - grenade:
-        #     irrelevant-files:
-        #       - ^.*\.rst$
-        #       - ^doc/.*$
+        - grenade:
+            irrelevant-files:
+              - ^.*\.rst$
+              - ^doc/.*$
         - openstacksdk-functional-devstack:
             irrelevant-files:
               - ^.*\.rst$