arm64: dts: qcom: sdm845-oneplus: Fix speaker GPIO node

Drop the unnecessary mux{} level to make dtbs check happy.
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230407-topic-msm_dtb-v1-6-6efb4196f51f@linaro.org

arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi

@@ -814,14 +814,12 @@ panel_esd_pin: panel-esd-state {
 	};
 
 	speaker_default: speaker-default-state {
-		mux {
 		pins = "gpio69";
 		function = "gpio";
 		drive-strength = <16>;
 		bias-pull-up;
 		output-high;
 	};
-	};
 };
 
 &venus {