dt-bindings: spmi: hisilicon,hisi-spmi-controller: clean up example

Clean up the binding example by dropping the unnecessary parent bus
node, using a define for the second register value of the PMIC child and
increasing indentation to four spaces.

Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20231130173757.13011-3-johan+linaro@kernel.org
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20240507210809.3479953-4-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>