drm/xe: Decouple job seqno and lrc seqno

Tightly coupling these seqno presents problems if alternative fences for
jobs are used. Decouple these for correctness.

v2:
- Slightly reword commit message (Thomas)
- Make sure the lrc fence ops are used in comparison (Thomas)
- Assume seqno is unsigned rather than signed in format string (Thomas)

Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240527135912.152156-2-thomas.hellstrom@linux.intel.com