PM: wakeup: Show statistics for deleted wakeup sources again

After commit 00ee22c2 (PM / wakeup: Use seq_open() to show wakeup
stats), print_wakeup_source_stats(m, &deleted_ws) is not called from
wakeup_sources_stats_seq_show() any more.

Because deleted_ws is one of the wakeup sources, it should be shown
too, so add it to the end of all other wakeup sources.

Signed-off-by: zhuguangqing <zhuguangqing@xiaomi.com>
[ rjw: Subject & changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>