drm/xe/bo: Don't include the CCS metadata in the dma-buf sg-table

drm/xe/bo: Don't include the CCS metadata in the dma-buf sg-table

Some Xe bos are allocated with extra backing-store for the CCS
metadata. It's never been the intention to share the CCS metadata
when exporting such bos as dma-buf. Don't include it in the
dma-buf sg-table.

Fixes: dd08ebf6c352 ("drm/xe: Introduce a new DRM driver for Intel GPUs")
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: <stable@vger.kernel.org> # v6.8+
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Karol Wachowski <karol.wachowski@linux.intel.com>
Link: https://patch.msgid.link/20251209204920.224374-1-thomas.hellstrom@linux.intel.com
(cherry picked from commit a4ebfb9d95d78a12512b435a698ee6886d712571)
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>