arm64: dts: qcom: sc8180x-primus: drop sound-dai-cells from eDisplayPort

Qualcomm MDSS Embedded DisplayPort bindings do not allow
sound-dai-cells:

  sc8180x-primus.dtb: displayport-controller@ae9a000: #sound-dai-cells: False schema does not allow [[0]]
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20231107103540.27353-1-krzysztof.kozlowski@linaro.orgSigned-off-by: Bjorn Andersson <andersson@kernel.org>

arch/arm64/boot/dts/qcom/sc8180x.dtsi

@@ -3113,8 +3113,6 @@ mdss_edp: displayport-controller@ae9a000 {
 				phys = <&edp_phy>;
 				phy-names = "dp";
 
-				#sound-dai-cells = <0>;
-
 				operating-points-v2 = <&edp_opp_table>;
 				power-domains = <&rpmhpd SC8180X_MMCX>;