toolkit/app-gen-toc.py: Use toolkit's config dir by default.

This change allows AToC config to use a default config file from
the toolkit's config dir, if custom one is not required (which is
true for most use cases). A custom config file can still be used
and customized by boards, by passing a different `--config-dir`.

Signed-off-by: iabdalkader <[email protected]>

Author: iabdalkader

toolkit/app-gen-toc.py

@@ -687,7 +687,7 @@ def main():
     parser.add_argument(
         "--config-dir",
         type=str,
-        default="",
+        default=Path(os.path.dirname(__file__)) / "build/config",
         help="directory with configuration files",
     )
     parser.add_argument(