added way to supply definesto cmake

cmake/scripts/cmake_build_config.py

@@ -26,6 +26,9 @@ def main():
                              "Information)", default="debug")
     parser.add_argument("-l", "--builddir", type=str, help="Specify build directory.")
     parser.add_argument("-g", "--generator", type=str, help="CMake Generator")
+    parser.add_argument("-d", "--defines",
+                        help="Additional custom defines passed to CMake (supply without -D prefix!)",
+                        nargs="*", type=str)
     parser.add_argument("-t", "--target-bsp", type=str, help="Target BSP, combination of architecture and machine")
 
     args = parser.parse_args()