arm64: dts: qcom: sm8350: fix pinctrl for UART18

On sm8350 QUP18 uses GPIO 68/69, not 58/59. Fix correponding UART18
pinconf configuraion.

Fixes: 98374e69 ("arm64: dts: qcom: sm8350: Set up WRAP2 QUPs")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20230825214550.1650938-1-dmitry.baryshkov@linaro.orgSigned-off-by: Bjorn Andersson <andersson@kernel.org>

arch/arm64/boot/dts/qcom/sm8350.dtsi

@@ -2965,7 +2965,7 @@ qup_uart6_default: qup-uart6-default-state {
 			};
 
 			qup_uart18_default: qup-uart18-default-state {
-				pins = "gpio58", "gpio59";
+				pins = "gpio68", "gpio69";
 				function = "qup18";
 				drive-strength = <2>;
 				bias-disable;