Rename the configure macros from atomic to sync

This is so I can add support for the new atomic's which
are named __atomic.

Signed-off-by: Angus Salkeld <asalkeld@redhat.com>
Add internal support for the new __atomic gcc builtins

Signed-off-by: Angus Salkeld <asalkeld@redhat.com>
Use the new atomic ops in the ringbuffer

Signed-off-by: Angus Salkeld <asalkeld@redhat.com>