staging: r8188eu: remove unused constants from wifi.h

The constants WLAN_REASON_PWR_CAPABILITY_NOT_VALID and
WLAN_REASON_SUPPORTED_CHANNEL_NOT_VALID defined in wifi.h
are unused, remove them.

Acked-by: Phillip Potter <phil@philpotter.co.uk>
Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20210829180717.15393-1-straube.linux@gmail.com


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