onboard netfilter upstream tree

Onboard the nf.git and nf-next.git trees:

• https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf.git
• https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next.git

arches:

all 4 arches

test:

networking/netfilter/upstream_test_wrapper (needs to pass TEST_URL="http://netqe-bj.usersys.redhat.com/share/yiche/kselftests.upstream.tar.gz" as test env parameters)