fix(utl-hpc.dfn): fix flopy subpackage metadata (#2182)

I think the final term here should be hpc_data, to follow the convention used for other subpackages and produce the generated files as they currently appear in flopy — at least assuming the same code is to handle all subpackages. Seems like there is inconsistent handling currently, depending whether they are attached to simulation or to a model or package.

doc/mf6io/mf6ivar/dfn/utl-hpc.dfn

@@ -1,5 +1,5 @@
 # --------------------- sim hpc options ---------------------
-# flopy subpackage hpc_filerecord hpc hpc_data hpc
+# flopy subpackage hpc_filerecord hpc hpc_data hpc_data
 # flopy parent_name_type parent_package MFSimulation
 
 block options