staging: r8188eu: clean up enum hw_variables

Remove unused constants from enum hw_variables.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20220209073618.29725-3-straube.linux@gmail.com


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