dt-bindings: phy: rockchip-inno-csi-dphy: make power-domains non-required

There are variants of the Rockchip Innosilicon CSI DPHY (e.g., the RK3568
variant) that are powered on by default as they are part of the ALIVE power
domain.
Remove 'power-domains' from the required properties in order to avoid false
positives.

Fixes: 22c8e0a6 ("dt-bindings: phy: add compatible for rk356x to rockchip-inno-csi-dphy")
Cc: stable@kernel.org
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Michael Riesch <michael.riesch@collabora.com>
Link: https://lore.kernel.org/r/20250616-rk3588-csi-dphy-v4-2-a4f340a7f0cf@collabora.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>