message: declare polynomfit class in linkdef
diff: #pragma link C++ class AliHLTTPCDefinitions+;
  #pragma link C++ class AliHLTTPCHistogramHandlerComponent+;
  #pragma link C++ class AliHLTTPCClusterAccessHLTOUT+;
  +#pragma link C++ class AliHLTTPCPolynomFit+;
  #pragma link C++ class AliHLTTPCCATrack+;
  #pragma link C++ class AliHLTTPCCATracklet+;
  #pragma link C++ class AliHLTTPCCATracker+;
  