peltool: Print the Words6To9 'Description' field

Include the 'Description' field from the Words6To9 registry entry when printing
SRC error details.

Changed from this:

"Error Details": {
    "Message":              "There was a failure when reading a sensor device",
    "CALLOUT_ERRNO":        "0x5"
}

to this:

"Error Details": {
    "Message":              "There was a failure when reading a sensor device",
    "CALLOUT_ERRNO": [
                            "0x5",
                            "errno of the failure"
    ]
}

Signed-off-by: Harisuddin Mohamed Isa <harisuddin@gmail.com>
Change-Id: Icc107b0516062eb891f14f3ff3f3cffd316c6d77
diff --git a/extensions/openpower-pels/registry.cpp b/extensions/openpower-pels/registry.cpp
index c8f10d7..755e829 100644
--- a/extensions/openpower-pels/registry.cpp
+++ b/extensions/openpower-pels/registry.cpp
@@ -15,6 +15,7 @@
  */
 #include "registry.hpp"
 
+#include "json_utils.hpp"
 #include "pel_types.hpp"
 #include "pel_values.hpp"
 
@@ -220,8 +221,9 @@
         }
 
         auto attributes = word.value();
-        std::string adPropName = attributes["AdditionalDataPropSource"];
-        hexwordFields[wordNum] = std::move(adPropName);
+        std::tuple<std::string, std::string> adPropSourceDesc(
+            attributes["AdditionalDataPropSource"], attributes["Description"]);
+        hexwordFields[wordNum] = std::move(adPropSourceDesc);
     }
 
     if (!hexwordFields.empty())