drm/xe: Mutual exclusivity between CCS-mode and PF

drm/xe: Mutual exclusivity between CCS-mode and PF

Due to SLA agreement between PF and VFs, currently we block CCS
mode changes if driver is running as PF, even if there are no VFs
enabled yet. Use lockdown mechanism provided by the PF to relax
that limitation and still enforce above VFs related requirements.

Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Nareshkumar Gollakoti <naresh.kumar.g@intel.com>
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patch.msgid.link/20260202170810.1393147-6-naresh.kumar.g@intel.com