drm/xe/pf: Introduce functions to configure VF thresholds

The GuC firmware monitors VF's activity and notifies the PF driver
once any configured threshold related to such activity is exceeded.
Add functions to allow configuration of these thresholds per VF.

Reviewed-by: Piotr Piórkowski <piotr.piorkowski@intel.com>
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240514190015.2172-5-michal.wajdeczko@intel.com