Staging: rt3090: rename device from raX to wlanX

This patch sets "wlan" as the default suffix for naming the device, a
change which has also been previously applied to rt2860/rt2870 in
staging.

Signed-off-by: Axel Koellhofer <rain_maker@root-forum.org>
Acked-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>