Merge tag 'xgene-dts-for-v4.4-1' of https://github.com/AppliedMicro/xgene-next into next/dt

Merge "X-Gene DTS changes queued for v4.4" from Duc Dang:

* tag 'xgene-dts-for-v4.4-1' of https://github.com/AppliedMicro/xgene-next:
  arm64: dts: Add poweroff device nodes for APM X-Gene 2 platform
  arm64: dts: Add APM X-Gene 2 standby GPIO controller DTS entries
  arm64: dts: Add PMU node for APM X-Gene Storm SOC
  Documentation: arm: pmu: Add Potenza PMU binding
  arm64: dts: Add X-Gene v2 reboot driver dts node
  arm64: dts: add APM Merlin Board device tree
  power: reset: Add syscon poweroff device node for APM X-Gene platform
  arm64: dts: Add X-Gene reboot driver dts node
  Documentation: arm64: add SCU dts binding documentation to linux kernel
  MAINTAINERS: Add Applied Micro (APM) X-Gene Device Tree maintainer