mfd: google,cros-ec: add missing properties

Add missing properties that are currently used in the examples of
subnode bindings and in many DTs.

Also updates the example in sound/google,cros-ec-codec.yaml to comply
with the google,cros-ec binding.

Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Ricardo Cañuelo <ricardo.canuelo@collabora.com>
Link: https://lore.kernel.org/r/20201021114308.25485-4-ricardo.canuelo@collabora.com
[robh: Add missing '#address-cells' and '#size-cells']
Signed-off-by: Rob Herring <robh@kernel.org>