Remove upstream Salt repos from models and replace with mcp repos

Fixes: PROD-22008 (PROD:22008)

Change-Id: I1537c55fef23d732952b944dc6f2dda3e37d02df
diff --git a/classes/cluster/os-ha-ovs-syndic/openstack/gateway.yml b/classes/cluster/os-ha-ovs-syndic/openstack/gateway.yml
index d38b87a..81171c5 100644
--- a/classes/cluster/os-ha-ovs-syndic/openstack/gateway.yml
+++ b/classes/cluster/os-ha-ovs-syndic/openstack/gateway.yml
@@ -1,7 +1,7 @@
 classes:
 - system.linux.system.repo.mcp.openstack
 - system.linux.system.repo.mcp.extra
-- system.linux.system.repo.saltstack.xenial
+- system.linux.system.repo.mcp.apt_mirantis.saltstack
 - system.neutron.gateway.cluster
 - cluster.virtual-mcp11-ovs
 parameters: