[cmake] Make sure Boost use std::atomic intead of its own implementation

Summary: Version 1.62 and earlier use by default some boost made atomics.

Test Plan: Build with ninja on linux and cross compile win32 and win64

Reviewers: #bitcoin_abc, schancel

Reviewed By: #bitcoin_abc, schancel

Subscribers: teamcity

Differential Revision: https://reviews.bitcoinabc.org/D1359