Disable wxDataObject in wxDFB build at configure level.

Otherwise we'd just get an error when compiling wx/dfb/chkconf.h later.

Closes #15594.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75049 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775