voicefont: make format version a parameter.

Make hardcoded format version a parameter to allow adjusting depending on the
installed Rockbox version. Rockbox Utility will read the version from the
installed version. Since the command line voicefont tool is only intended for
use in the current tree it uses a fixed version.

Change-Id: I1ec935d47c71961e93b3c6bc6c5d816cd9fc83ff

rbutil/rbutilqt/base/voicefile.h

@@ -67,6 +67,7 @@ private:
     QString m_lang;  // the language which will be spoken
     QString m_versionstring; // version string to be used for logging
     int m_wavtrimThreshold;
+    int m_voiceformat;
 
     bool m_abort;
     QList<TalkGenerator::TalkEntry> m_talkList;