Make cmake config file optional.

CMake/CMakeCABMacros.cmake

CMake/CMakeSetCompilerFlags.cmake

CMake/cmake_config_files/BILBO.config.cmake

CMake/cmake_config_files/ELLADAN.config.cmake

CMake/cmake_config_files/GOTTFRIED.config.cmake

CMake/cmake_config_files/PHOENIX.config.cmake

CMake/cmake_config_files/SMAUG.config.cmake

CMake/cmake_config_files/SUPERMUC.config.cmake

CMake/cmake_config_files/TESLA01.config.cmake

CMake/cmake_config_files/UBUNTU.config.cmake

CMake/cmake_config_files/YWANG.config.cmake

CMakeLists.txt

apps/cpu/LidDrivenCavityCPU/CMakeLists.txt