spi: dt-bindings: nuvoton,wpcm450-fiu: Drop unrelated nodes from DTS example

Binding example should not contain other nodes, including other
providers like syscon, because this is redundant and only adds
unnecessary bloat.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://patch.msgid.link/20250509112130.123462-4-krzysztof.kozlowski@linaro.org


Signed-off-by: Mark Brown <broonie@kernel.org>