PCI: PCIe portdrv: Fix suspend and resume of PCI Express port services

There is a problem with the suspend and resume of PCI Express port
service devices that the ->suspend() and ->resume() routines of each
service device are called twice in each suspend-resume cycle, which
is obviously wrong.

The scenario is that first, the PCI Express port driver calls
suspend and resume routines of each port service driver from its
pcie_portdrv_suspend() and pcie_portdrv_resume() callbacks,
respectively (which is correct), and second, the pcie_port_bus_type
driver calls them from its ->suspend() and ->resume() callbacks
(which is not correct, because it doesn't happen at the right time).

The solution is to remove the ->suspend() and ->resume() callbacks
from pcie_port_bus_type and the associated functions.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>