drm/xe: Don't trigger rebind on initial dma-buf validation

On the first validate of an imported dma-buf (initial bind), the device
has no GPU mappings, so a rebind is unnecessary. Rebinding here is
harmful in multi-GPU setups and for VMs using preempt-fence mode, as it
would evict in-flight GPU work.

v2:
 - Drop dma_buf_validated, check for XE_PL_SYSTEM (Thomas)

Fixes: dd08ebf ("drm/xe: Introduce a new DRM driver for Intel GPUs")
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://lore.kernel.org/r/20250825152841.3837378-1-matthew.brost@intel.com
(cherry picked from commit ffdf968)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

Author: mbrost05

drivers/gpu/drm/xe/xe_bo.c

@@ -812,7 +812,8 @@ static int xe_bo_move(struct ttm_buffer_object *ttm_bo, bool evict,
 	}
 
 	if (ttm_bo->type == ttm_bo_type_sg) {
-		ret = xe_bo_move_notify(bo, ctx);
+		if (new_mem->mem_type == XE_PL_SYSTEM)
+			ret = xe_bo_move_notify(bo, ctx);
 		if (!ret)
 			ret = xe_bo_move_dmabuf(ttm_bo, new_mem);
 		return ret;