forked from Mirrors/opensbi

"gpio-poweroff" and "gpio-restart" always set gpio to high to active the function, but some chips need a low signal to active. Fortunately, it can be achieved by setting GPIO_FLAG_ACTIVE_LOW for the gpio. Implement this flag support for the gpio library so the gpio reset can function well. Signed-off-by: Inochi Amaoto <inochiama@outlook.com> Reviewed-by: Anup Patel <anup@brainfault.org>