staging: r8188eu: RFType is set but never used

RFType is set but never used. Remove it from struct HAL_VERSION and
remove the now unused enum HAL_RF_TYPE.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20211129230125.27247-1-straube.linux@gmail.com


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