Move HAVE_SUITESPARSE and dune_register_package_flags to AddSuiteSparseFlags

cmake/modules/AddSuiteSparseFlags.cmake

@@ -10,6 +10,18 @@
 #       A list of targets to use SuiteSparse with.
 #
 
+# set HAVE_SUITESPARSE for config.h
+set(HAVE_SUITESPARSE ${SuiteSparse_FOUND})
+set(HAVE_UMFPACK ${SuiteSparse_UMFPACK_FOUND})
+
+# register all SuiteSparse related flags
+if(SuiteSparse_FOUND)
+  dune_register_package_flags(
+    COMPILE_DEFINITIONS "ENABLE_SUITESPARSE=1"
+    LIBRARIES SuiteSparse::SuiteSparse)
+endif()
+
+# Provide function to set target properties for linking to SuiteSparse
 function(add_dune_suitesparse_flags _targets)
   if(SuiteSparse_FOUND)
     foreach(_target ${_targets})