x86 platform driver: intelligent power sharing driver

Intel Core i3/5 platforms with integrated graphics support both CPU and
GPU turbo mode.  CPU turbo mode is opportunistic: the CPU will use any
available power to increase core frequencies if thermal headroom is
available.  The GPU side is more manual however; the graphics driver
must monitor GPU power and temperature and coordinate with a core
thermal driver to take advantage of available thermal and power headroom
in the package.

The intelligent power sharing (IPS) driver is intended to coordinate
this activity by monitoring MCP (multi-chip package) temperature and
power, allowing the CPU and/or GPU to increase their power consumption,
and thus performance, when possible.  The goal is to maximize
performance within a given platform's TDP (thermal design point).

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Matthew Garrett <mjg@redhat.com>