drm/xe/pf: Expose SR-IOV policy settings over debugfs

We already have functions to configure SR-IOV policies.
Allow to tweak those policy settings over debugfs.

Reviewed-by: Piotr Piórkowski <piotr.piorkowski@intel.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240423131244.2045-4-michal.wajdeczko@intel.com