staging: rtl8723bs: remove unused rtw_rf_config module param

remove unused rtw_rf_config module param and struct field
used to store the param value.

Signed-off-by: Fabio Aiuto <fabioaiuto83@gmail.com>
Link: https://lore.kernel.org/r/a83eaa9b2350d3d16f5b1dddc40870e0f0a6df06.1628329348.git.fabioaiuto83@gmail.com


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