drm/xe: Allow compute VMs to output dma-fences on binds

Binds are not long running jobs thus we can export dma-fences even if a
VM is in compute mode.

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>