RHEL 7.3 provides upstream tunnel but it does not support name_assign_type
attribute in net-device. This patch fixes the build problem by backporting
functions with name_assign_type, and using proper flags in acinclude.m4 to
invoke backport functions.
Tested on RHEL 7.3 with kernel 3.10.0-514.el7.x86_64
Signed-off-by: Yi-Hung Wei <yihung.wei@gmail.com>
Signed-off-by: Joe Stringer <joe@ovn.org>