PEL: Fix message registry schema typo

Change-Id: Ic20d6560a79dc8cc871ebc1ab64ce5aefc2ccfe6
diff --git a/extensions/openpower-pels/registry/schema/schema.json b/extensions/openpower-pels/registry/schema/schema.json
index 10fdff9..f41d425 100644
--- a/extensions/openpower-pels/registry/schema/schema.json
+++ b/extensions/openpower-pels/registry/schema/schema.json
@@ -227,7 +227,7 @@
             "description": "The event scope PEL field. Optional and defaults to entire_platform",
             "type": "string",
             "enum": ["entire_platform", "single_partition", "multiple_partitions",
-                     "possibly_multiple_partitions"]
+                     "possibly_multiple_platforms"]
         },
 
         "eventType":