Revert "PCI: pciehp: Add runtime PM support for PCIe hotplug ports"

Revert "PCI: pciehp: Add runtime PM support for PCIe hotplug ports"

This reverts commit c715ec78e360db78bfb387f539378424f1038036.

Yinghai reported that the following manual hotplug sequence:

  # echo 0 > /sys/bus/pci/slots/8/power
  # echo 1 > /sys/bus/pci/slots/8/power

worked in v4.9, but fails in v4.10-rc1, and that reverting c715ec78e360
("PCI: pciehp: Add runtime PM support for PCIe hotplug ports") makes it
work again.

Fixes: c715ec78e360 ("PCI: pciehp: Add runtime PM support for PCIe hotplug ports")
Link: https://lkml.kernel.org/r/CAE9FiQVCMCa7iVyuwp9z6VrY0cE7V_xghuXip28Ft52=8QmTWw@mail.gmail.com
Link: https://bugzilla.kernel.org/show_bug.cgi?id=193951
Reported-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>