Add MTU to single_ovs_br_floating and single_ovs_br_prv

Change-Id: Ida7029c4a1ba3b358d902ee51ff29c21d695831f
diff --git "a/\173\043 roles \043\175/_linux_network_interface" "b/\173\043 roles \043\175/_linux_network_interface"
index c94af4d..85de14f 100644
--- "a/\173\043 roles \043\175/_linux_network_interface"
+++ "b/\173\043 roles \043\175/_linux_network_interface"
@@ -18,6 +18,7 @@
         'tenant_network_gateway',
         'dns_server01',
         'dns_server02',
+        'mtu',
     ]
 %}
 {%- set interface_roles = {} %}