Staging: rt*: don't confuse user of rt3070 driver with rt2870 strings

Original author didn't bother to change strings for rt3070 driver. Fix it.

Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Acked-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>