staging: r8188eu: remove module parameter rtw_rf_config

The module parameter rtw_rf_config is not used in the driver.
Remove it and remove the now unused enum rt_rf_type_def.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20211128170924.5874-11-straube.linux@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>