When powering off the whole system, we should power off some external
subsystems' connection firstly, otherwise some external subsystems
will hold some power and result in powering down abnormally.
Signed-off-by: Sherry Zong <sherry.zong@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang7@gmail.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>