dhcp ip: DSCP settings for transmitted DHCP packets

Type: feature

- Define the ip_dscp_t and use in the IP headers
- Add DSCP setting to the DHCP client for use with packet TX

Change-Id: If220dde0017ea78793747d65f53e11daf23a28fa
Signed-off-by: Neale Ranns <nranns@cisco.com>
diff --git a/test/vpp_papi_provider.py b/test/vpp_papi_provider.py
index e40ef79..f9bb470 100644
--- a/test/vpp_papi_provider.py
+++ b/test/vpp_papi_provider.py
@@ -1032,7 +1032,8 @@
                            client_id='',
                            is_add=1,
                            set_broadcast_flag=1,
-                           want_dhcp_events=0):
+                           want_dhcp_events=0,
+                           dscp=0):
         return self.api(
             self.papi.dhcp_client_config,
             {
@@ -1043,6 +1044,7 @@
                     'id': client_id,
                     'want_dhcp_event': want_dhcp_events,
                     'set_broadcast_flag': set_broadcast_flag,
+                    'dscp': dscp,
                     'pid': os.getpid()}
             })