The power management controller found on Apple SoCs als provides a way to reset all devices within a power domain. This is needed to cleanly shutdown the NVMe controller before we hand over control to the OS. Signed-off-by: Mark Kettenis <kettenis@openbsd.org> Reviewed-by: Simon Glass <sjg@chromium.org> Tested on: Macbook Air M1 Tested-by: Simon Glass <sjg@chromium.org> Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>