staging: rtl8723bs: remove unused code blocks conditioned by never set CONFIG_DISABLE_MCS13TO15

remove conditional code blocks checked by unused
CONFIG_DISABLE_MCS13TO15

cleaning required in TODO file:

find and remove code blocks guarded by never set CONFIG_FOO defines

Signed-off-by: Fabio Aiuto <fabioaiuto83@gmail.com>
Link: https://lore.kernel.org/r/54e5805534f920d8c443874b759560a6127c8db8.1615907632.git.fabioaiuto83@gmail.com


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