r92su: RX_STATUS_DESC -> RX_DESC

Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
r92su: port wildcard scan feature from vendor driver

Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
r92su: start adhoc mode

This patch adds some preliminary functions for ad-hoc mode.
r92su: fix type of length in ssid field

Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>