Merge changes from topic "allwinner_h616" into integration

* changes:
  allwinner: H616: Add reserved-memory node to DT
  allwinner: Add Allwinner H616 SoC support
  allwinner: Add H616 SoC ID
  allwinner: Express memmap more dynamically
  allwinner: Move sunxi_cpu_power_off_self() into platforms
  allwinner: Move SEPARATE_NOBITS_REGION to platforms
  doc: allwinner: Reorder sections, document memory mapping