[CMake] Remove HAVE_PARMETIS from config.h.cmake

It belongs to dune-common's config.h.cmake. Otherwise
it cannot be shared with other modules using ParMETIS.

config.h.cmake

@@ -34,11 +34,6 @@
 /* Define to ENABLE_BOOST if the Boost library is available */
 #cmakedefine HAVE_BOOST ENABLE_BOOST
 
-/* Define to ENABLE_PARMETIS if you have the Parmetis library.
-   This is only true if MPI was found
-   by configure _and_ if the application uses the PARMETIS_CPPFLAGS */
-#cmakedefine HAVE_PARMETIS ENABLE_PARMETIS
-
 /* Define to ENABLE_SUPERLU if the SuperLU library is available */
 #cmakedefine HAVE_SUPERLU ENABLE_SUPERLU