drm/xe/configfs: Don't expose survivability_mode if not applicable

drm/xe/configfs: Don't expose survivability_mode if not applicable

The survivability_mode attribute is applicable only for DGFX and
platforms newer than BATTLEMAGE. Use .is_visible() hook to hide
this attribute when above conditions are not met. Remove code that
was trying to fix such configuration during the runtime.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Riana Tauro <riana.tauro@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Stuart Summers <stuart.summers@intel.com>
Link: https://lore.kernel.org/r/20250902131744.5076-4-michal.wajdeczko@intel.com