If sched lock before irq save, and irq handler do post, scheduler will
be delayed after WFI until next sched unlock. which is not acceptable.
Signed-off-by: buxiasen <buxiasen@xiaomi.com>
pm process should be done by chip specific, but we can provide a standard
flow, then vendor & chip can only focus on handle different state change.
Signed-off-by: buxiasen <buxiasen@xiaomi.com>