COMP: Populate vtklibproj4 link interface

This was missed in the cleanup-CMP0022-CMP0023 branch.

Change-Id: Icb4625345e24561f21b540a9e86c2c02ab0b54c9
Merge topic 'vtkproj4-linking' into master

c549f584 COMP: Populate vtklibproj4 link interface