ethdev: revert use port name from device structure

ethdev: revert use port name from device structure

This reverts commit a1e7c17555e8f77d520ba5f06ed26c00e77a2bd1.

Original commit assumes there is 1:1 mapping between physical device and
ethdev port, so that device name can be used per port instead of ethdev
name field.

But one physical device may have multiple ethdev ports and each port
needs its own unique name.

One issue reported here:
http://dpdk.org/ml/archives/users/2017-September/002484.html

So reverting back the commit to continue using ethdev name field per
port.

Fixes: a1e7c17555e8 ("ethdev: use device name from device structure")
Cc: stable@dpdk.org
Reported-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>
Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
Acked-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>
Acked-by: Thomas Monjalon <thomas@monjalon.net>