bus/pci: check IO permissions for UIO only

bus/pci: check IO permissions for UIO only

On x86, calling inb/outb special instructions (used in UIO ioport
read/write parts) is only possible if the right IO permissions has been
granted.

The only user of this API (the net/virtio pmd) checks this
unconditionnaly but this should be hidden by the rte_pci_ioport API
itself and only checked when the device is bound to a UIO driver.

Signed-off-by: David Marchand <david.marchand@redhat.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>