Fix dvcs_ps_gen includes

benchmarks/dvcs/analysis/dvcs_ps_gen.cxx

+#include "TH2F.h"
+#include "TLorentzVector.h"
+#include "TGenPhaseSpace.h"
+
 void dvcs_ps_gen() {
   double E_p = 100.0;
   double M_p = 0.938;