Prune new rc service name php_fpm

Summary:
FreeBSD package for PHP has renamed the rc service from php-fpm to php_fpm.

Delete that php_fpm service, as we publish ours, with multiple pools support,
under the old name. That avoids confusion during autocomplete.

Ref T1341

Test Plan: Deployed on WindRiver

Reviewers: dereckson

Reviewed By: dereckson

Maniphest Tasks: T1341

Differential Revision: https://devcentral.nasqueron.org/D3512