drm/xe/uapi: Remove DRM_XE_UFENCE_WAIT_MASK_*

Those are just possible values for the comparison mask but they are not
specific magic values. Let's keep them as examples in the documentation
but remove them from the uAPI.

Suggested-by: Matthew Brost <matthew.brost@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Acked-by: José Roberto de Souza <jose.souza@intel.com>
Acked-by: Mateusz Naklicki <mateusz.naklicki@intel.com>
Signed-off-by: Francois Dugast <francois.dugast@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>