drm/xe: Remove xe_lrc_create_seqno_fence()

It's not used anymore.

Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240527135912.152156-5-thomas.hellstrom@linux.intel.com