{rua,hnbap,ranap}_common: Add missing encoding functions

We used to only have those generator functions that we needed for
the existing hnbgw code; Implement the missing encoders
diff --git a/src/ranap_common.h b/src/ranap_common.h
index 4ffa613..84b4976 100644
--- a/src/ranap_common.h
+++ b/src/ranap_common.h
@@ -591,12 +591,22 @@
 
 extern int asn1_xer_print;
 
+struct msgb *ranap_generate_initiating_message(e_RANAP_ProcedureCode procedureCode,
+					  RANAP_Criticality_t criticality,
+					  asn_TYPE_descriptor_t *td, void *sptr);
+
 struct msgb *ranap_generate_successful_outcome(
 					   e_RANAP_ProcedureCode procedureCode,
 					   RANAP_Criticality_t criticality,
 					   asn_TYPE_descriptor_t * td,
 					   void *sptr);
 
+struct msgb *ranap_generate_unsuccessful_outcome(
+					e_RANAP_ProcedureCode procedureCode,
+					RANAP_Criticality_t criticality,
+					asn_TYPE_descriptor_t * td,
+					void *sptr);
+
 RANAP_IE_t *ranap_new_ie(RANAP_ProtocolIE_ID_t id, RANAP_Criticality_t criticality,
 			 asn_TYPE_descriptor_t *type, void *sptr);