Changes

lint/lint_diff: run clang-format if config was found

The osmo-asf4-dfu and osmo-ccid-firmware now have clang-format configs.
Adjust the lint script to run clang-format if such a config is found in
the repository for which the lint script is running.

Change-Id: Ie210966ebfbada43dd8507b9b48218df4925820d