ranap: New ranap_new_msg_initial_ue() funcition

for testing, it is useful if we can also generate an InitialUE
message - even though a HNB-GW only needs to receive it.
diff --git a/src/ranap_msg_factory.h b/src/ranap_msg_factory.h
index 3bc73e1..e48b1bf 100644
--- a/src/ranap_msg_factory.h
+++ b/src/ranap_msg_factory.h
@@ -33,3 +33,9 @@
 /*! \brief generate RANAP RESET ACK message */
 struct msgb *ranap_new_msg_reset_ack(RANAP_CN_DomainIndicator_t domain,
 				     RANAP_GlobalRNC_ID_t *rnc_id);
+
+
+/*! \brief generate RANAP INITIAL UE message */
+struct msgb *ranap_new_msg_initial_ue(uint32_t conn_id, int is_ps,
+				     RANAP_GlobalRNC_ID_t *rnc_id,
+				     uint8_t *nas_pdu, unsigned int nas_len);