Sending tunnel interface 'up' command to NR UE

Once the LTE UE's tunnel interface with the EPC
is ready to be established, if we are in NSA mode,
we do not want to launch the tunnel interface
from the LTE UE side, but in the NR UE. Via itti_msgs
we send the string containing the tunnel interface
'up' command to the NR UE and bring it up from the NR UE.

openair2/COMMON/as_message.h

@@ -219,6 +219,10 @@ typedef struct kenb_refresh_req_s {
   Byte_t kenb[32];
 } kenb_refresh_req_t;
 
+typedef struct nsa_oai_tun_nsa_s {
+  uint8_t buffer[500]; //Melissa TODO
+} nas_oai_tun_nsa_t;
+
 /*
  * NAS->AS - Cell Information request
  * NAS request AS to search for a suitable cell belonging to the selected