PEL: peltool: Add const strings for section header

Added "Section Version", "Sub-section type" and "Created by" constant strings.

Updated all getJSON() functions to use the new constants.

Signed-off-by: Harisuddin Mohamed Isa <harisuddin@gmail.com>
Change-Id: I434192afed929972845c3cfb8876cc5ef784eec2
diff --git a/extensions/openpower-pels/failing_mtms.cpp b/extensions/openpower-pels/failing_mtms.cpp
index b45c05d..386f496 100644
--- a/extensions/openpower-pels/failing_mtms.cpp
+++ b/extensions/openpower-pels/failing_mtms.cpp
@@ -17,6 +17,7 @@
 
 #include "json_utils.hpp"
 #include "pel_types.hpp"
+#include "pel_values.hpp"
 
 #include <phosphor-logging/log.hpp>
 
@@ -25,6 +26,7 @@
 namespace pels
 {
 
+namespace pv = openpower::pels::pel_values;
 using namespace phosphor::logging;
 static constexpr uint8_t failingMTMSVersion = 0x01;
 
@@ -89,12 +91,10 @@
 std::optional<std::string> FailingMTMS::getJSON() const
 {
     std::string json;
-    jsonInsert(json, "Section Version", getNumberString("%d", _header.version),
-               1);
-    jsonInsert(json, "Sub-section type", getNumberString("%d", _header.subType),
-               1);
-    jsonInsert(json, "Created by", getNumberString("0x%X", _header.componentID),
-               1);
+    jsonInsert(json, pv::sectionVer, getNumberString("%d", _header.version), 1);
+    jsonInsert(json, pv::subSection, getNumberString("%d", _header.subType), 1);
+    jsonInsert(json, pv::createdBy,
+               getNumberString("0x%X", _header.componentID), 1);
     jsonInsert(json, "Machine Type Model", _mtms.machineTypeAndModel(), 1);
     jsonInsert(json, "Serial Number", trimEnd(_mtms.machineSerialNumber()), 1);
     json.erase(json.size() - 2);