rtl8712: remove unused macros from rtl8712/wifi.h

Those definitions are not used anywhere in the kernel. If you know any
reason why they should stay in the code please speak up!

Signed-off-by: Przemo Firszt <przemo@firszt.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>