Prior to adding dt-bindings for SoC-dependent controllers, rename the
parent node to the generic name in the example.

And drop a parent node of the nvmem as it is not directly necessary here.
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20221213082449.2721-9-hayashi.kunihiko@socionext.comSigned-off-by: Rob Herring <robh@kernel.org>