FROMGIT: power: reset: sc27xx: Power off the external subsystems' connection

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.

bug: 146864653
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>
(cherry picked from commit 6cdd5b09cbe67365c42aee539f6fd00f2ecfdaab
https://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-power-supply.git for-next)