eal/freebsd: add config reattach in secondary process

eal/freebsd: add config reattach in secondary process

Linux EAL will attach the shared config at an arbitrary address,
find out where the shared config is mapped in the primary, and
then will reattach it at that exact address.

FreeBSD version doesn't seem to go for that extra reattach step,
which makes one wonder how did it ever work in the first place.

Fix the FreeBSD init to also reattach shared config to the exact
same place the primary process has it.

Fixes: 764bf26873b9 ("add FreeBSD support")
Cc: stable@dpdk.org
Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Reviewed-by: David Marchand <david.marchand@redhat.com>