Adding libfyaml dependency to the psp version

spack_repo/packages/icon-nwp/package.py

@@ -61,6 +61,7 @@ class IconNwp(Package):
     depends_on("libxml2")
 
     depends_on("petsc", when="@psp")
+    depends_on("libfyaml", when="@psp")
     depends_on("petsc", when="+petsc")
     depends_on("tenstream", when="@plexrt")
     depends_on("tenstream", when="+plexrt")