PM / sleep: Check pm_wakeup_pending() in __device_suspend_noirq()

Restore the pm_wakeup_pending() check in __device_suspend_noirq()
removed by commit eed4d47e

 (ACPI / sleep: Ignore spurious SCI
wakeups from suspend-to-idle) as that allows the function to return
earlier if there's a wakeup event pending already (so that it may
spend less time on carrying out operations that will be reversed
shortly anyway) and rework the main suspend-to-idle loop to take
that optimization into account.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>