Revert "qt: Disable Qt modules when support is unavailable"

This reverts commit 9ccbad3d0622a693e3de3c0e0033844551361554.

The logic was incorrect. ParaView ensures that these modules are not
enabled when Qt support is disabled. However, if user still manually
enables these modules, it should indeed find Qt and fail appropriately.

Change-Id: I3806e58beff7eba04039c90e05073de86f0e02b6
Merge topic 'fix_qt_modules' into next

c5ef697d Revert "qt: Disable Qt modules when support is unavailable"