dt-bindings: Add Sercomm (Suzhou) Corporation vendor prefix

Add "sercomm" vendor prefix for "Sercomm (Suzhou) Corporation".

Company website:
Link: https://www.sercomm.com/



Signed-off-by: Mikhail Zhilkin <csharper2005@gmail.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220516151637.885324-1-csharper2005@gmail.com