arm64: dts: qcom: sm8350: drop incorrect cells from serial

The serial/UART device node does not have children with unit addresses,
so address/size cells are not correct.

Fixes: cf03cd7e ("arm64: dts: qcom: sm8350: Set up WRAP0 QUPs")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230124084951.38195-2-krzysztof.kozlowski@linaro.org