ethdev: get port by name

ethdev: get port by name

Converted rte_eth_dev_get_port_by_name to a public API.
Converted rte_eth_dev_get_name_by_port to a public API.

The librte_pdump library provides the APIs to enable or disable the
packet capture either using the port id or pci address or device name.
So pdump library need to do a mapping from name to port and port to name
internally to validate the device name and register the Rx and Tx
callbacks for the mapped ports. So these APIs are made public for the
pdump library for doing the mentioned mappings.

Signed-off-by: Reshma Pattan <reshma.pattan@intel.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>