amd-xgbe: Add support to handle device renaming

Many of the names used by the driver are based upon the name of the device
found during device probe.  Move the formatting of the names into the
device open function so that any renaming that occurs before the device is
brought up will be accounted for.  This also means moving the creation of
some named workqueues into the device open path.

Add support to register for net events so that if a device is renamed
the corresponding debugfs directory can be renamed.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>