Use the CMakeLists.txt for IS_NEWER_THAN

The directory isn't updated every build necessarily
but the CMakeLists.txt itself is regenerated often.

This should improve the consistency of changing
targets & re-loading the cmake project

Test: make && reload cmake in clion
Change-Id: I5a184ea9c626f03d70f6dc3a5e05646ee33cfe2f
1 file changed