ACPI: PM: Do not turn off power resources in unknown state

Commit 6381195a ("ACPI: power: Rework turning off unused power
resources") caused power resources in unknown state with reference
counters equal to zero to be turned off too, but that caused issues
to appear in the field, so modify the code to only turn off power
resources that are known to be "on".

Link: https://lore.kernel.org/linux-acpi/6faf4b92-78d5-47a4-63df-cc2bab7769d0@molgen.mpg.de/
Fixes: 6381195a

 ("ACPI: power: Rework turning off unused power resources")
Reported-by: Andreas K. Huettel <andreas.huettel@ur.de>
Tested-by: Andreas K. Huettel <andreas.huettel@ur.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: 5.14+ <stable@vger.kernel.org> # 5.14+