media: dt-bindings: imx7-csi: Make power-domains not required for imx8mq

On i.MX8MQ the MIPI CSI block does have an associated power-domain, but
the CSI bridge does not.

Remove the power-domains requirement from the i.MX8MQ CSI bridge
to fix the following schema warning:

imx8mq-librem5-r4.dtb: csi@30a90000: 'power-domains' is a required property
from schema $id: http://devicetree.org/schemas/media/nxp,imx7-csi.yaml#



Fixes: de655386 ("media: dt-bindings: media: imx7-csi: Document i.MX8M power-domains property")
Signed-off-by: Fabio Estevam <festevam@denx.de>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Link: https://lore.kernel.org/r/20231004201105.2323758-1-festevam@gmail.com


Signed-off-by: Rob Herring <robh@kernel.org>