PM: suspend: Make pm_test delay interruptible by wakeup events

PM: suspend: Make pm_test delay interruptible by wakeup events

Modify the suspend_test() function to allow the test delay to be
interrupted by wakeup events.

This improves the responsiveness of the system during suspend testing
when wakeup events occur, allowing the suspend process to proceed
without waiting for the full test delay to complete when wakeup events
are detected.

Additionally, using msleep() instead of mdelay() avoids potential soft
lockup "CPU stuck" issues when long test delays are configured.

Co-developed-by: xiongxin <xiongxin@kylinos.cn>
Signed-off-by: xiongxin <xiongxin@kylinos.cn>
Signed-off-by: Riwen Lu <luriwen@kylinos.cn>
[ rjw: Changelog edits ]
Link: https://patch.msgid.link/20251113012638.1362013-1-luriwen@kylinos.cn
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>