drm/xe/bo: Redirect faults to dummy page for wedged device

drm/xe/bo: Redirect faults to dummy page for wedged device

As per uapi documentation[1], the prerequisite for wedged device is to
redirected page faults to a dummy page. Follow it.

[1] Documentation/gpu/drm-uapi.rst

v2: Add uapi reference and fixes tag (Matthew Brost)

Fixes: 7bc00751f877 ("drm/xe: Use device wedged event")
Signed-off-by: Raag Jadav <raag.jadav@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patch.msgid.link/20260212055622.2054991-1-raag.jadav@intel.com
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>