Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFtbemd:

Use MACHINE_CPUARCH in preference to MACHINE_ARCH. The former is the
source code location of the machine, the latter the binary output. In
general, we want to use MACHINE_CPUARCH instead of MACHINE_ARCH unless
we're tesitng for a specific target. The isn't even moot for
i386/amd64 where there's momemntum towards a MACHINE_CPUARCH == x86,
although a specific cleanup for that likely would be needed...

Introduce the new kernel sub-tree x86 which should contain all the code
shared and generalized between our current amd64, i386 and pc98.

This is just an initial step that should lead to a more complete effort.
For the moment, a very simple porting of cpufreq modules, BIOS calls and
the whole MD specific ISA bus part is added to the sub-tree but ideally
a lot of code might be added and more shared support should grow.

Sponsored by: Sandvine Incorporated
Reviewed by: emaste, kib, jhb, imp
Discussed on: arch
MFC: 3 weeks

Import ACPICA 20090521.

Introduce support for cpufreq on PowerPC with the dynamic frequency
switching capabilities of the MPC7447A and MPC7448.

Add support for Phenom (Family 10h) to cpufreq.
Its a newer version provided by the author than in the PR.

PR: kern/128575
Submitted by: Gen Otsuji annona2 [at] gmail.com

Dike out WARNS from kernel module makefiles. Kernels and modules
use a different mechanism for setting warning flags, and using
WARNS here only has null or negative effects.

Submitted by: bde (I think it means "submitted")

Add a driver for SMI-based SpeedStep. The hardware supports two frequency
settings and is an older version of the same design used for ICH SpeedStep.
It is only known to be available on PIIX4 chipsets.

Many thanks to Bruno Ducrot for writing the driver and Jon Noack for
testing.

Submitted by: Bruno Ducrot

Add support for _PDC/_OSC by advertising that we support direct access to
the PERF_CTL/STS MSRs via the new acpi_get_features() method. This should
allow newer systems to use SpeedStep.

Additions to .PATH are cumulative so referencing $.PATH is not helpful.

Informed by: ru

Fix module build on amd64. There may be a cleaner way to do the .PATH

Hook powernow up to the build for i386 and amd64.

Hook p4tcc up to the module build.

Hook EST up to the build.

Hook up the cpufreq framework, acpi_perf(4), and cpufreq(4) drivers.