dt-bindings: arm: aspeed: document board compatibles

Document jabil board compatible.

Signed-off-by: David Wang <David_Wang6097@jabil.com>
Link: https://lore.kernel.org/r/20220531011100.882643-2-David_Wang6097@jabil.com


Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>