ethdev: remove driver name from device private data

ethdev: remove driver name from device private data

rte_driver->name has the driver name and all physical and virtual
devices has access to it.

Previously it was not possible for virtual ethernet devices to access
rte_driver->name field (because eth_dev used to keep only pci_dev),
and it was required to save driver name in the device private struct.

After re-works on bus and vdev, it is possible for all bus types to
access rte_driver.

It is able to remove the driver name from ethdev device private data and
use eth_dev->device->driver->name.

Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
Acked-by: Shreyansh Jain <shreyansh.jain@nxp.com>
Acked-by: Jan Blunck <jblunck@infradead.org>