mfem: link to nveccuda when +sundials+cuda (#20588)

var/spack/repos/builtin/packages/mfem/package.py

@@ -723,6 +723,8 @@ def sundials_components(self):
                 sun_comps += ',nvecparallel,nvecmpiplusx'
             else:
                 sun_comps += ',nvecparhyp,nvecparallel'
+        if '+cuda' in self.spec:
+            sun_comps += ',nveccuda'
         return sun_comps
 
     @property