Tweaks to src/utl/CMakeLists.txt for macOS
Tweaks to src/utl/CMakeLists.txt for macOS

Signed-off-by: Don MacMillen <1f1e67e5fdb25d2e5cd18ddc0fee425272daab56@macmillen.net>

The-OpenROAD-Project/OpenROAD,The-OpenROAD-Project/OpenROAD,The-OpenROAD-Project/OpenROAD,QuantamHD/OpenROAD,The-OpenROAD-Project/OpenROAD,QuantamHD/OpenROAD,QuantamHD/OpenROAD,The-OpenROAD-Project/OpenROAD,QuantamHD/OpenROAD,QuantamHD/OpenROAD