PCI: PCIe portdrv: Do not enable port device before setting up interrupts

The PCI Express port driver calls pci_enable_device() before setting
up interrupts, which is wrong, because if there is an interrupt pin
configured for the port, pci_enable_device() will likely set up an
interrupt link for it.  However, this shouldn't be done if either
MSI or MSI-X interrupt mode is chosen for the port.

The solution is to call pci_enable_device() after setting up
interrupts, because in that case the interrupt link won't be set up
if MSI or MSI-X are enabled.

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