wireless: zd1211rw: new url for fw, remove experimental

Cc: Daniel Drake <dsd@laptop.org>
Cc: Ulrich Kunitz <kune@deine-taler.de>
Cc: John W. Linville <linville@tuxdriver.com>
Cc: linux-wireless@vger.kernel.org
Signed-off-by: Xose Vazquez Perez <xose.vazquez@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>