lldp: cleanup when there is no lldp interface

lldp/init.sls

+{%- set lldp = False -%}
+{%- for name, interface in pillar.ifaces.items() if 'lldp' in interface -%}
+  {%- do lldp = True -%}
+{%- endfor -%}
+{%- if lldp -%}
 lldpd:
   pkg.installed: []
   service.running:
@@ -14,3 +19,11 @@ lldpd:
     - mode: 644
     - template: jinja
     - source: salt://lldp/files/default-lldp.j2
+{%- else %}
+purge-lldpd:
+  pkg.purged: lldpd
+
+purge-lldpd-default:
+  file.absent:
+    - filename: /etc/default/lldpd
+{% endif %}