Remove unused .cu files

Accelerators/Vtkm/vtkmlib/DataSetConverters.cu

-//=============================================================================
-//
-//  Copyright (c) Kitware, Inc.
-//  All rights reserved.
-//  See LICENSE.txt for details.
-//
-//  This software is distributed WITHOUT ANY WARRANTY; without even
-//  the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
-//  PURPOSE.  See the above copyright notice for more information.
-//
-//  Copyright 2012 Sandia Corporation.
-//  Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
-//  the U.S. Government retains certain rights in this software.
-//
-//=============================================================================
-#include "DataSetConverters.cxx"

Accelerators/Vtkm/vtkmlib/ImplicitFunctionConverter.cu

-//=============================================================================
-//
-//  Copyright (c) Kitware, Inc.
-//  All rights reserved.
-//  See LICENSE.txt for details.
-//
-//  This software is distributed WITHOUT ANY WARRANTY; without even
-//  the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
-//  PURPOSE.  See the above copyright notice for more information.
-//
-//  Copyright 2012 Sandia Corporation.
-//  Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
-//  the U.S. Government retains certain rights in this software.
-//
-//=============================================================================
-#include "ImplicitFunctionConverter.cxx"

Accelerators/Vtkm/vtkmlib/Portals.cu

-//=============================================================================
-//
-//  Copyright (c) Kitware, Inc.
-//  All rights reserved.
-//  See LICENSE.txt for details.
-//
-//  This software is distributed WITHOUT ANY WARRANTY; without even
-//  the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
-//  PURPOSE.  See the above copyright notice for more information.
-//
-//  Copyright 2012 Sandia Corporation.
-//  Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
-//  the U.S. Government retains certain rights in this software.
-//
-//=============================================================================
-#include "Portals.cxx"