sysutils/devcpu-data follow up commit to 20180108 Intel microcode update.

Run cpucontrol -e after microcode update to refresh cpu flags. If running
on an older system without -e, fail silently.

Log any upgrade output via logger to /var/log/messages.

Add an instructional pkg-message for users.

Intel Release Notes:
Intel Processor Microcode Package for Linux
20180108 Release

• Updates upon 20171117 release --

IVT C0 (06-3e-04:ed) 428->42a
SKL-U/Y D0 (06-4e-03:c0) ba->c2
BDW-U/Y E/F (06-3d-04:c0) 25->28
HSW-ULT Cx/Dx (06-45-01:72) 20->21
Crystalwell Cx (06-46-01:32) 17->18
BDW-H E/G (06-47-01:22) 17->1b
HSX-EX E0 (06-3f-04:80) 0f->10
SKL-H/S R0 (06-5e-03:36) ba->c2
HSW Cx/Dx (06-3c-03:32) 22->23
HSX C0 (06-3f-02:6f) 3a->3b
BDX-DE V0/V1 (06-56-02:10) 0f->14
BDX-DE V2 (06-56-03:10) 700000d->7000011
KBL-U/Y H0 (06-8e-09:c0) 62->80
KBL Y0 / CFL D0 (06-8e-0a:c0) 70->80
KBL-H/S B0 (06-9e-09:2a) 5e->80
CFL U0 (06-9e-0a:22) 70->80
CFL B0 (06-9e-0b:02) 72->80
SKX H0 (06-55-04:b7) 2000035->200003c
GLK B0 (06-7a-01:01) 1e->22

Reviewed by: A bunch of folks on the review
MFH: 2018Q1
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D13815