ethdev: add unique name to devices

ethdev: add unique name to devices

Adding support to rte_eth_dev_data structure to support unique
name identifier for ethdevs to support adding slave ethdevs
(specifically virtual devices which have no public unique
identifier) to a link bonding device. This changes the API
rte_eth_dev_allocate() to require a const char *name when
allocating a ethdev, which also verifies that the name is
unique and hasn’t been already used by an existed allocated
rte_eth_dev. Also contains updates to virtual pmd’s to now call
the API with a name parameter.

Signed-off-by: Declan Doherty <declan.doherty@intel.com>
Acked-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>