use NGS fork in epoxy

to get [1]

[1] https://review.opendev.org/c/openstack/networking-generic-switch/+/973461

Signed-off-by: Bartosz Bezak <bartosz@stackhpc.com>

Author: bbezak

etc/kayobe/kolla.yml

@@ -135,6 +135,10 @@ kolla_sources:
     type: git
     location: https://github.com/stackhpc/stackhpc-inspector-plugins.git
     reference: 1.3.0
+  neutron-base-plugin-networking-generic-switch:
+    type: git
+    location: https://github.com/stackhpc/networking-generic-switch.git
+    reference: stackhpc/{{ openstack_release }}
   neutron-server-plugin-networking-mlnx:
     type: git
     location: https://github.com/stackhpc/networking-mlnx.git