devel/libatomic_ops: update 7.8.0 -> 7.10.0

Changelog: https://github.com/bdwgc/libatomic_ops/releases/tag/v7.10.0

Major port changes: Transfer repo to bdwgc organization
see https://github.com/bdwgc/bdwgc/issues/741

Reported by: Ivan Maidanski <ivmai@mail.ru> (via CTSRD-CHERI pullrequest 226)