drm/xe: Add GT frequency sanity and management with GuC PC.
First of all this patch brings some sanity to the frequencies that GuC is selecting. Right now GuC selects some really high RPMax frequency as max default. This doesn't make any sense without any overclocking. Let's bring the maximum to the hardware RP0.
Then, let's also introduce the sysfs interfaces for controlling these frequency limits.
Signed-off-by: Rodrigo Vivi rodrigo.vivi@intel.com