drm/xe: Introduce RC6 support with GuCRC.
We should keep it simple and reuse all the GuC PC's defaults. As for sysfs, for now let's only introduce the immediate status and the residency counter.
Let's delegate the counter-to-milliseconds conversion and the overflow handling to user space, for simplicity, at least for now.
Signed-off-by: Rodrigo Vivi rodrigo.vivi@intel.com