The TX descriptors setup for AR971 requires the same
setup as AR9285, so use that.
Signed-off-by: Sujith <Sujith.Manoharan@atheros.com> Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com> Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>