pastix: Propagate StarPU.

Fixes #1.

* inria/hiepacs.scm (pastix)[inputs]: Move STARPU to...
[propagated-inputs]: ... here.

inria/hiepacs.scm

@@ -391,7 +391,6 @@ features, such as: namespaces, templates, exceptions, etc.")
 
        ;; The following are optional dependencies.
        ("metis" ,metis)
-       ("starpu" ,starpu)
 
        ;; Python bindings and Python tests.
        ;;
@@ -402,7 +401,11 @@ features, such as: namespaces, templates, exceptions, etc.")
 
        ("python-numpy" ,python2-numpy)
        ("python-scipy" ,python2-scipy)))
+
+    ;; 'pastix.pc' requires 'starpu-mpi-1.2.pc' and 'hwloc.pc', so propagate
+    ;; them.
     (propagated-inputs `(("hwloc" ,hwloc "lib")
+                         ("starpu" ,starpu)
                          ("scotch" ,scotch)))
     (synopsis "Sparse matrix direct solver")
     (description