drm/xe/xe_hw_error: Add fault injection to trigger csc error handler

drm/xe/xe_hw_error: Add fault injection to trigger csc error handler

Add a debugfs fault handler to trigger csc error handler that
wedges the device and enables runtime survivability mode.

v2: add debugfs only for bmg (Umesh)
v3: do not use csc_fault attribute if debugfs is not enabled
v4: rebase

Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Riana Tauro <riana.tauro@intel.com>
Reviewed-by: Raag Jadav <raag.jadav@intel.com>
Link: https://lore.kernel.org/r/20250826063419.3022216-11-riana.tauro@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>