arm64: dts: qcom: msm8992: Add a label to rpm-requests

This enables the node to be referenced directly from other
DTs.

Signed-off-by: Konrad Dybcio <konradybcio@gmail.com>
Link: https://lore.kernel.org/r/20200624150107.76234-4-konradybcio@gmail.com


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