drm/xe/pf: Promote PF debugfs function to its own file

drm/xe/pf: Promote PF debugfs function to its own file

In upcoming patches, we will build on the PF separate debugfs
tree for all SR-IOV related files and this new code will need
dedicated file. To minimize large diffs later, move existing
function now as-is, so any future modifications will be done
directly in target file.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/20250928140029.198847-2-michal.wajdeczko@intel.com