kernel/3.10: improve fq_codel hashing for 6in4 6to4 801.ad and IPIP cases

This is a backport of code to improve the quality of fq_codel
hashing for 3.10 for some encapsulated protocols.

Not needed in 3.11 and later.

Patch-by: Dave Taht <dave.taht@bufferbloat.net>
Patchwork: http://patchwork.openwrt.org/patch/4902/


Signed-off-by: Gabor Juhos <juhosg@openwrt.org>

SVN-Revision: 39640