arm64: dts: qcom: msm8996: override nodes by label

Using node paths to extend or override a device tree node is error
prone.  If there was a typo error, a new node will be created instead of
extending the existing node.  This will lead to run-time errors that
could be hard to detect.

A mistyped label on the other hand, will cause a dtc compile error
(during build time).  This also reduces the indentation making the code
easier to read.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220402192859.154977-2-krzysztof.kozlowski@linaro.org