Configure dhcp relay in Maas fabrics

PROD-31910

Change-Id: I80d5a15fc38be0793c680da8c6bfd24b2e9f407e
diff --git a/_states/maasng.py b/_states/maasng.py
index 96fe529..5c68652 100644
--- a/_states/maasng.py
+++ b/_states/maasng.py
@@ -372,7 +372,7 @@
     return ret
 
 
-def vlan_present_in_fabric(name, fabric, vlan, primary_rack, description='', dhcp_on=False, mtu=1500):
+def vlan_present_in_fabric(name, fabric, vlan, primary_rack, description='', dhcp_on=False, mtu=1500, relay_vlan=None):
     """
 
     :param name: Name of vlan
@@ -405,7 +405,8 @@
                                                            mtu=mtu,
                                                            description=description,
                                                            primary_rack=primary_rack,
-                                                           dhcp_on=dhcp_on)
+                                                           dhcp_on=dhcp_on,
+                                                           relay_vlan=relay_vlan)
         ret['comment'] = 'Vlan {0} has ' \
                          'been created for {1}'.format(name, fabric)
     elif _rez == 'update':
@@ -418,7 +419,8 @@
                                                            primary_rack=primary_rack,
                                                            dhcp_on=dhcp_on,
                                                            update=True,
-                                                           vlan_id=_id)
+                                                           vlan_id=_id,
+                                                           relay_vlan=relay_vlan)
         ret['comment'] = 'Vlan {0} has been ' \
                          'updated for {1}'.format(name, fabric)
     ret['changes'] = changes