staging:r8188eu: remove unused definitions from wifi.h

These definitions are not used and will not be useful in the future.

Signed-off-by: Ivan Safonov <insafonov@gmail.com>
Link: https://lore.kernel.org/r/20210314090247.21181-3-insafonov@gmail.com


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