AETHER-1828 Add support of external IP for AMF service

This allows exposing SCTP port not limited to nodePort range

Change-Id: I1c6b2a4d499b05b64b5d04ae5ed8705322e85e42
diff --git a/omec/5g-control-plane/templates/service-amf.yaml b/omec/5g-control-plane/templates/service-amf.yaml
index 5e37bdf..6900dba 100644
--- a/omec/5g-control-plane/templates/service-amf.yaml
+++ b/omec/5g-control-plane/templates/service-amf.yaml
@@ -36,6 +36,10 @@
 {{ tuple "amf" . | include "5g-control-plane.metadata_labels" | indent 4 }}
 spec:
   type: NodePort
+{{- if .Values.config.amf.ngapp.externalIp }}
+  externalIPs:
+    - {{ .Values.config.amf.ngapp.externalIp }}
+{{- end }}
   selector:
 {{ tuple "amf" . | include "5g-control-plane.metadata_labels" | indent 4 }}
   ports: