Add proper cpu scaling support for amd cpus

[Andrew Berg]

On 2013.12.04 11:58, Adrian Chadd wrote:
> Which branch did you update on? HEAD? Or?
# svnlite info /usr/src
Path: /usr/src
Working Copy Root Path: /usr/src
URL: https://svn0.us-west.freebsd.org/base/stable/10
Relative URL: ^/stable/10
Repository Root: https://svn0.us-west.freebsd.org/base
Repository UUID: ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
Revision: 258901
Node Kind: directory
Schedule: normal
Last Changed Author: tuexen
Last Changed Rev: 258890
Last Changed Date: 2013-12-03 14:55:37 -0600 (Tue, 03 Dec 2013)

I've not looked at HEAD.