needed for upcoming PCI_D3cold support.

This patch has no functionality change, because pci_set_power_state
will bound the parameter to PCI_D3hot too.

CC: Michal Miroslaw <mirq-linux@rere.qmqm.pl>
CC: Jesse Barnes <jesse.barnes@intel.com>
Reviewed-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>\®
ˆ•.x