Refine trunk interface

MTU / IP_MTU -> to role's vars

geant/gap_ansible/roles/iptrunk/templates/nokia/trunk_interface.j2

@@ -27,7 +27,7 @@
           <description>PHY INFRASTRUCTURE BACKBONE P_{{ local.ae_name }} | {{ trunk_direction_name_sorted[0] }}-{{ trunk_direction_name_sorted[1] }} | {{ member.interface_description }}</description>
           <ethernet>
               <mode>network</mode>
-              <mtu>9212</mtu>
+              <mtu>{{ mtu_phy }}</mtu>
               <lldp>
                   <dest-mac>
                       <mac-type>nearest-bridge</mac-type>
@@ -82,7 +82,7 @@
               <interface-name>{{ local.ae_name | lower }}.0</interface-name>
               <admin-state>enable</admin-state>
               <description>SRV_GLOBAL INFRASTRUCTURE BACKBONE #{{ trunk_direction_name_sorted[0] }}-{{ trunk_direction_name_sorted[1] }}-IPTRUNK ${{ trunk.id }}| {{ trunk_direction_name_sorted[0] }}-{{ trunk_direction_name_sorted[1] }} | {{ common.description }}</description>
-              <ip-mtu>9000</ip-mtu>
+              <ip-mtu>{{ mtu_ip }}</ip-mtu>
               <port>{{ local.ae_name | lower }}</port>
               <ipv4>
                   <primary>