Set ramdisk logs path for ironic inspector

If the [processing] ramdisk_logs_dir option is set, logs returned by the
ironic inspection ramdisk following hardware inspection will be stored
at that location. This enables easier debugging if inspection fails.

Change-Id: I36bdf75c04b088b67b5f54fdf20251c10bdddb63

ansible/roles/ironic/templates/ironic-inspector.conf.j2

@@ -39,3 +39,6 @@ dnsmasq_interface = {{ ironic_dnsmasq_interface }}
 
 [database]
 connection = mysql+pymysql://{{ ironic_inspector_database_user }}:{{ ironic_inspector_database_password }}@{{ ironic_inspector_database_address }}/{{ ironic_inspector_database_name }}
+
+[processing]
+ramdisk_logs_dir = /var/log/kolla/ironic-inspector

releasenotes/notes/inspector-ramdisk-logs-9623a734c4d56410.yaml

+---
+upgrade:
+  - |
+    The Bare Metal Inspection service is now configured to store logs from the
+    inspection ramdisk in the ``kolla_logs`` Docker volume.