Define error and metadata yaml for procedure callouts

OpenPOWER systems defines maintenance procedure callouts, which points
to a specific procedure that needs to be executed on the server in
order to identify the faulty hardware and repair the error. Each
maintenance procedure is documented externally.

Change-Id: Id4d9da38c6b13951cd0731ad25cea0d39c74bca0
Signed-off-by: Tom Joseph <tomjoseph@in.ibm.com>
diff --git a/org/open_power/Host.errors.yaml b/org/open_power/Host.errors.yaml
index c48f3ed..ab3df62 100644
--- a/org/open_power/Host.errors.yaml
+++ b/org/open_power/Host.errors.yaml
@@ -1,2 +1,5 @@
 - name: Event
   description: A host system event was received
+
+- name: MaintenanceProcedure
+  description: A host system event with a procedure callout