Add Kokkos support for fix shake and forward comm on Device

src/fix.cpp

@@ -111,6 +111,7 @@ Fix::Fix(LAMMPS *lmp, int /*narg*/, char **arg) :
   datamask_modify = ALL_MASK;
 
   kokkosable = 0;
+  forward_comm_device = 0;
   copymode = 0;
 }