arm64: dts: qcom: msm8916: Add CPU ACC and SAW/SPM

Add the device tree nodes necessary for SMP bring-up and cpuidle
without PSCI on ARM32. The hardware is typically controlled by the
PSCI implementation in the TrustZone firmware and is therefore marked
as status = "reserved" by default (from the device tree specification):

  "Indicates that the device is operational, but should not be used.
   Typically this is used for devices that are controlled by another
   software component, such as platform firmware."

Since this is part of the MSM8916 SoC it should be added to msm8916.dtsi
but in practice these nodes should only get enabled via an extra include
on ARM32.

This is necessary for some devices with signed firmware which is missing
both ARM64 and PSCI support and can therefore only boot ARM32 kernels.

Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20211004204955.21077-13-stephan@gerhold.net