cmake: Fix sst object lib dependency propagation with CMake < 3.14
Created by: bradking
CMake < 3.14 forget to propagate private dependencies of object libraries. Propagate them the same way CMake >= 3.14 do.
Created by: bradking
CMake < 3.14 forget to propagate private dependencies of object libraries. Propagate them the same way CMake >= 3.14 do.