sysutils/devcpu-data: Temporarily return to the tree

Re-add the port to give users time to adjust to the reorganization of
the CPU microcode ports in bc7829212d153aeff69b439d08e2e3001ef88ba3.

Reported by: dch
Reviewed by: manu
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D41718