drm/xe/vf: Don't try Driver-FLR if VF

Driver-FLR can't be triggered from the VF driver, so treat it
as disabled if VF. While around, fix also the message, as it
shouldn't be printed just 'once' as we may have many devices.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250311135726.1998-2-michal.wajdeczko@intel.com