arm64: dts: qcom: ipq6018: Sort nodes properly

Order nodes by unit address if one exists and alphabetically otherwise.
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230102094642.74254-4-konrad.dybcio@linaro.org