PEL: Use uppercase hex in message registry

The code in the Registry class requires the ReasonCode field in the
message registry to use upper case hex digits (A-F) to be able to find a
match to print the description in peltool, so change the message
registry schema to require that.  Also fix an entry that had lower case.

Alternatively, the code could be fixed, but with the schema checking
that runs in CI to catch errors this method seems less impactful.

Signed-off-by: Matt Spinler <spinler@us.ibm.com>
Change-Id: I4f26c876575be58232f1408f9357465a3340002a
diff --git a/extensions/openpower-pels/registry/message_registry.json b/extensions/openpower-pels/registry/message_registry.json
index aa4d41a..935f79f 100644
--- a/extensions/openpower-pels/registry/message_registry.json
+++ b/extensions/openpower-pels/registry/message_registry.json
@@ -839,9 +839,9 @@
             "Name": "org.open_power.Faultlog.Error.DeconfiguredHW",
             "Subsystem": "cec_hardware",
             "Severity": "predictive",
-            "ComponentID": "0xf100",
+            "ComponentID": "0xF100",
             "SRC": {
-                "ReasonCode": "0xf138",
+                "ReasonCode": "0xF138",
                 "Words6To9": {
                     "6": {
                         "Description": "Number of guard records with error object",