dt-bindings: display: imx: Add i.MX8qxp Display Controller command sequencer

i.MX8qxp Display Controller contains a command sequencer is designed to
autonomously process command lists.

Signed-off-by: Liu Ying <victor.liu@nxp.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20250414035028.1561475-7-victor.liu@nxp.com