cmTimestamp: Expose CreateTimestampFromTimeT publicly

Source/cmTimestamp.h

@@ -23,12 +23,12 @@ public:
                                    const std::string& formatString,
                                    bool utcFlag);
 
-private:
-  time_t CreateUtcTimeTFromTm(struct tm& timeStruct) const;
-
   std::string CreateTimestampFromTimeT(time_t timeT, std::string formatString,
                                        bool utcFlag) const;
 
+private:
+  time_t CreateUtcTimeTFromTm(struct tm& timeStruct) const;
+
   std::string AddTimestampComponent(char flag, struct tm& timeStruct,
                                     time_t timeT) const;
 };