Merge changes from topic "rk3288" into integration

* changes:
  rockchip: document platform
  rockchip: add support for rk3288
  rockchip: add common aarch32 support
  rockchip: rk3328: drop double declaration of entry_point storage
  rockchip: Allow socs with undefined wfe check bits
  rockchip: move pmusram assembler code to a aarch64 subdir
  sp_min: allow inclusion of a platform-specific linker script
  sp_min: make sp_min_warm_entrypoint public
  drivers: ti: uart: add a aarch32 variant