Make sure amgcl can be used without CUDA

opm/simulators/linalg/ISTLSolverEbos.hpp

@@ -265,9 +265,12 @@ namespace Opm
                 WellContributions wellContribs(accelerator_mode, useWellConn_);
                 bdaBridge->initWellContributions(wellContribs);
 
+                // the WellContributions can only be applied separately with CUDA or OpenCL, not with an FPGA or amgcl
+#if HAVE_CUDA || HAVE_OPENCL
                 if (!useWellConn_) {
                     simulator_.problem().wellModel().getWellContributions(wellContribs);
                 }
+#endif
 
                 // Const_cast needed since the CUDA stuff overwrites values for better matrix condition..
                 bdaBridge->solve_system(const_cast<Matrix*>(&getMatrix()), *rhs_, wellContribs, result);

opm/simulators/linalg/bda/amgclSolverBackend.hpp

@@ -30,18 +30,19 @@
 
 #include <amgcl/amg.hpp>
 #include <amgcl/backend/builtin.hpp>
-#include <amgcl/backend/cuda.hpp>
-#include <amgcl/relaxation/cusparse_ilu0.hpp>
 #include <amgcl/adapter/crs_tuple.hpp>
 #include <amgcl/make_block_solver.hpp>
 #include <amgcl/relaxation/as_preconditioner.hpp>
 #include <amgcl/relaxation/ilu0.hpp>
 #include <amgcl/solver/bicgstab.hpp>
-
 #include <amgcl/preconditioner/runtime.hpp>
-
 #include <amgcl/value_type/static_matrix.hpp>
 
+#if HAVE_CUDA
+#include <amgcl/backend/cuda.hpp>
+#include <amgcl/relaxation/cusparse_ilu0.hpp>
+#endif
+
 #define AMGCL_CUDA 0
 
 namespace bda