PCI/ASPM: Deallocate upstream link state even if device is not PCIe

On PCI bus hotplug removal, pcie_aspm_exit_link_state() can potentially
skip parent devices that have link_state allocated.  Instead of exiting
early if a given device is not PCIe, check whether or not the device's
parent has link_state allocated.  This enables pcie_aspm_exit_link_state()
to properly clean up parent link_state when the last function in a slot
might not be PCIe.

Reported-by: Joe Lawrence <joe.lawrence@stratus.com>
Tested-by: Joe Lawrence <joe.lawrence@stratus.com>
Signed-off-by: Myron Stowe <myron.stowe@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>