crda
This reverts commit eb657c45f9. Prepare for `crda` removal from `nixpkgs`. According to upstream https://lore.kernel.org/linux-wireless/455bafff0d609eb182ba30a5fbf319888e0e961d.camel@sipsolutions.net/ `crda` is not needed for kernels `4.16` or later. Such old kernels are not in `nixpkgs` anymore.
eb657c45f9