drm/xe/guc: Add VF_CFG_SCHED_PRIORITY_KEY KLV definition

This KLV allows to set the scheduling priority for each VF, also
for the PF.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Lukasz Laguna <lukasz.laguna@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241106151301.2079-2-michal.wajdeczko@intel.com