drm/xe/vf: Custom GuC initialization if VF

The GuC firmware is loaded and initialized by the PF driver. Make
sure VF drivers only perform permitted operations. For submission
initialization, use number of GuC context IDs from self config.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Piotr Piórkowski <piotr.piorkowski@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240521092518.624-3-michal.wajdeczko@intel.com