dt-bindings: arm: airoha: Add the chip-scu node for EN7581 SoC

dt-bindings: arm: airoha: Add the chip-scu node for EN7581 SoC

This patch adds the chip-scu document bindings for EN7581 SoC.
The airoha chip-scu block provides a configuration interface for clock,
io-muxing and other functionalities used by multiple controllers (e.g.
clock, pinctrl, ecc.) on EN7581 SoC.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/20241023-en7581-pinctrl-v9-1-afb0cbcab0ec@kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>