PCI: Restrict device disabled status check to DT

PCI: Restrict device disabled status check to DT

Commit 6fffbc7ae137 ("PCI: Honor firmware's device disabled status")
checked the firmware device status for both DT and ACPI devices. That
caused a regression in some ACPI systems. The exact reason isn't clear.
It's possibly a firmware bug. For now, at least, refactor the check to
be for DT based systems only.

Note that the original implementation leaked a refcount which is now
correctly handled.

[bhelgaas: Per ACPI r6.5, sec 6.3.7, for devices on an enumerable bus, _STA
must return with bit[0] ("device is present") set]

Link: https://lore.kernel.org/all/m2fs9lgndw.fsf@gmail.com/
Fixes: 6fffbc7ae137 ("PCI: Honor firmware's device disabled status")
Link: https://lore.kernel.org/r/20230419193513.708818-1-robh@kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=217317
Reported-by: Donald Hunter <donald.hunter@gmail.com>
Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Donald Hunter <donald.hunter@gmail.com>
Tested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Binbin Zhou <zhoubinbin@loongson.cn>
Cc: Liu Peibao <liupeibao@loongson.cn>
Cc: Huacai Chen <chenhuacai@loongson.cn>