dt-bindings: serial: sc16is7xx: move 'allOf' block after 'required'

The 'allOf' block should go after the 'required' block according to DT
bindings best practices.

Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20231013141925.3427158-2-hugo@hugovil.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>