Fix Qt4 atomics on aarch64. Add a patch from Fedora (similar changes in
Arch and Debian) that implements the atomics; removes the use of generic
atomics on aarch64. This allows textproc/qt4-dbus to build.

PR: 223988
Reported by: linimon
Approved by: tcberner (mentor)
Obtained from: Fedora (url is in patch)
Differential Revision: https://reviews.freebsd.org/D13935