arm64: dts: qcom: sm8450-hdk: use recommended drive strength for speaker SD_N

Downstream DTS (and sc8280xp-lenovo-thinkpad-x13s with the same
speakers) uses 16 mA drive strength for the WSA8835 speaker SD_N
reset/shutdown pin.  Use the same for HDK8450, as it is seem the
recommended value.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230308142712.277659-1-krzysztof.kozlowski@linaro.org