PEL: Install an empty PEL message registry

This will eventually contain the information to create PELs out of
OpenBMC event logs.  It is installed into
/usr/share/phosphor-logging/pels.

Signed-off-by: Matt Spinler <spinler@us.ibm.com>
Change-Id: Iaf67881890a47f605af3ae69b54f186b63915ca6
diff --git a/extensions/openpower-pels/registry/message_registry.json b/extensions/openpower-pels/registry/message_registry.json
new file mode 100644
index 0000000..e2f2ac2
--- /dev/null
+++ b/extensions/openpower-pels/registry/message_registry.json
@@ -0,0 +1,6 @@
+{
+    "PELs":
+    [
+
+    ]
+}