arm64: dts: qcom: sm8250: correct Soundwire node name

arm64: dts: qcom: sm8250: correct Soundwire node name

Soundwire Devicetree bindings expect the Soundwire controller device
node to be named just "soundwire":

  sm8250-xiaomi-elish-boe.dtb: soundwire-controller@3250000: $nodename:0: 'soundwire-controller@3250000' does not match '^soundwire(@.*)?$'

Reported-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20231107102111.16465-2-krzysztof.kozlowski@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>