PCI/PM: Set current_state to D3cold if the device is not accessible

Make pci_power_up() and pci_set_low_power_state() change current_state
to PCI_D3cold when the device is not accessible along the lines of
pci_update_current_state().

Link: https://lore.kernel.org/r/10104376.nUPlyArG6x@kreacher


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