arm64: dts: qcom: sdm845: move sound node out of soc

The sound node is not a property of a soc, but rather board as it
describes the sound configuration.  It also does not have unit address:

  sdm845-shift-axolotl.dtb: soc@0: sound: {} should not be valid under {'type': 'object'}

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221210115704.97614-3-krzysztof.kozlowski@linaro.org