PCI: Fix pcie_port_device_resume() comment

The function comment claimed this was pcie_port_device_suspend(), but it's
really pcie_port_device_resume().  Perils of cut and paste.

Use the correct function name in the comment.

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