pci: allow drivers to be bound several times to the same PCI device

pci: allow drivers to be bound several times to the same PCI device

Drivers with the flag RTE_PCI_DRV_MULTIPLE enabled will be bound several
times to the same device until they return an error.

These drivers must internally keep track of each device state in order for
this to work reliably.

This flag currently required for Ethernet adapters with several physical
ports but a single address on the PCI bus.

Signed-off-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>
Acked-by: Ivan Boule <ivan.boule@6wind.com>
Acked-by: Damien Millescamps <damien.millescamps@6wind.com>