Hipified common kernels. HIP can't compile Eigen.

CMakeLists.txt

include/connectivity.h

include/eigen.h

include/entity_data.h

include/gmsh_io.h

include/gpu_support.hpp

include/kernels_gpu.h

include/maxwell_interface.h

include/physical_element.h

include/reference_element.h

include/types.h

src/entity.cpp

src/maxwell_common.cpp

src/maxwell_gpu.cpp

src/maxwell_interface.cpp