This gets rid of previously deprecated driver_ops handlers set_wpa,
set_drop_unencrypted, set_auth_alg, set_mode. The same functionality
can be achieved by using the init/deinit/associate handlers.
These driver wrappers should not be used anymore; WEXT should be used
instead. However, there may still be users stuck on older kernel versions
that may require driver specific wrappers, so the source code still
remains in the repository.