Wrapping/Tcl: Restore "pvtk" build
Wrapping/Tcl: Restore "pvtk" build

The pvtk executable was dropped during modularization.  Restore its
build rules, now conditioned on presence of the vtkParallelMPI module.

Change-Id: Id3cd9639d08770deb5a04d7103ce420e633540e6

demarle/VTK,hendradarwin/VTK,johnkit/vtk-dev,ashray/VTK-EVM,msmolens/VTK,sankhesh/VTK,berendkleinhaneveld/VTK,SimVascular/VTK,sumedhasingla/VTK,aashish24/VTK-old,berendkleinhaneveld/VTK,sankhesh/VTK,msmolens/VTK,biddisco/VTK,keithroe/vtkoptix,biddisco/VTK,johnkit/vtk-dev,demarle/VTK,demarle/VTK,ashray/VTK-EVM,SimVascular/VTK,SimVascular/VTK,aashish24/VTK-old,mspark93/VTK,sumedhasingla/VTK,ashray/VTK-EVM,gram526/VTK,msmolens/VTK,jmerkow/VTK,berendkleinhaneveld/VTK,johnkit/vtk-dev,candy7393/VTK,sumedhasingla/VTK,mspark93/VTK,ashray/VTK-EVM,sankhesh/VTK,berendkleinhaneveld/VTK,jmerkow/VTK,biddisco/VTK,keithroe/vtkoptix,ashray/VTK-EVM,candy7393/VTK,msmolens/VTK,aashish24/VTK-old,aashish24/VTK-old,mspark93/VTK,collects/VTK,gram526/VTK,msmolens/VTK,gram526/VTK,collects/VTK,johnkit/vtk-dev,SimVascular/VTK,ashray/VTK-EVM,biddisco/VTK,collects/VTK,hendradarwin/VTK,gram526/VTK,demarle/VTK,hendradarwin/VTK,jmerkow/VTK,aashish24/VTK-old,SimVascular/VTK,biddisco/VTK,candy7393/VTK,candy7393/VTK,collects/VTK,keithroe/vtkoptix,hendradarwin/VTK,jmerkow/VTK,demarle/VTK,collects/VTK,jmerkow/VTK,keithroe/vtkoptix,hendradarwin/VTK,mspark93/VTK,sankhesh/VTK,keithroe/vtkoptix,msmolens/VTK,jmerkow/VTK,mspark93/VTK,aashish24/VTK-old,jmerkow/VTK,candy7393/VTK,sankhesh/VTK,msmolens/VTK,candy7393/VTK,berendkleinhaneveld/VTK,biddisco/VTK,keithroe/vtkoptix,mspark93/VTK,ashray/VTK-EVM,sumedhasingla/VTK,demarle/VTK,sumedhasingla/VTK,mspark93/VTK,hendradarwin/VTK,berendkleinhaneveld/VTK,sumedhasingla/VTK,demarle/VTK,sumedhasingla/VTK,johnkit/vtk-dev,gram526/VTK,mspark93/VTK,sankhesh/VTK,gram526/VTK,sankhesh/VTK,gram526/VTK,SimVascular/VTK,sumedhasingla/VTK,ashray/VTK-EVM,candy7393/VTK,johnkit/vtk-dev,collects/VTK,gram526/VTK,SimVascular/VTK,sankhesh/VTK,candy7393/VTK,msmolens/VTK,berendkleinhaneveld/VTK,SimVascular/VTK,jmerkow/VTK,hendradarwin/VTK,keithroe/vtkoptix,johnkit/vtk-dev,biddisco/VTK,demarle/VTK,keithroe/vtkoptix