In order to enable FPM in your PHP build you need to add --enable-fpm
to your configure line.
There are several other FPM-specific configure options (all of them optional):
--with-fpm-user - set FPM user (default - nobody).
--with-fpm-group - set FPM group (default - nobody).
--with-fpm-systemd - Activate systemd integration (default - no).
--with-fpm-acl - Use POSIX Access Control Lists (default - no). Since PHP 5.6.5.