dt-bindings: mtd: Add Samsung S5Pv210 OneNAND

Document binding for Samsung S5Pv210 SoC OneNAND controller used already
in S5Pv210 DTS.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20240313184317.18466-1-krzysztof.kozlowski@linaro.org