A rogue wakeup source not registered in wakeup_sources list is not visible
from wakeup_sources_stats_show. Check if the wakeup source is registered
properly by looking at the timer struct.
Signed-off-by: NJin Qian <jinqian@android.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>