arm64: dts: qcom: msm8976: Add restart node

Add a pshold restart node what can be found in downstream for
enable to perform restart operations.

Signed-off-by: Barnabás Czémán <barnabas.czeman@mainlining.org>
Link: https://lore.kernel.org/r/20240807-pshold-v1-1-0fa7927e99ce@mainlining.org


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