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.org


Signed-off-by: Bjorn Andersson <andersson@kernel.org>