kernel: stable updates

 - 3.13 stable:   3.13.3  -> 3.13.4
 - 3.12 stable:   3.12.11 -> 3.12.12
 - 3.10 longterm: 3.10.30 -> 3.10.31
 - 3.4  longterm: 3.4.80  -> 3.4.81

Signed-off-by: Austin Seipp <aseipp@pobox.com>