PCI: pciehp: Always implement resume, regardless of pciehp_force param

Previously, the driver ignored resume unless the pciehp_force module_param
was specified.  On some laptops that means that interrupts are not
delivered after S3, so card removals and insertions are not handled.
This patch makes the driver handle resume regardless of pciehp_force.

[bhelgaas: changelog]
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rjw@sisk.pl>