stmmac: debugfs entry name is not be changed when udev rename device name.

Add one notifier for udev changes net device name.
Fixes: b6601323ef9e ("net: stmmac: debugfs entry name is not be changed when udev rename")

Signed-off-by: Jiping Ma <jiping.ma2@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>