net: Use standard MDIO interface for AXXIA FEMAC Driver

commit bd8cdb05 from
https://github.com/axxia/linux-yocto.git

 v5.10/standard/axxia-dev/base.

Removed the manual MDIO bus code from the Intel AXXIA FEMAC
driver and added code to use the standard linux MDIO interface.

Signed-off-by: Charlie Paul <charlie.paul@windriver.com>
Signed-off-by: John Jacques <john.jacques@intel.com>
Signed-off-by: Daniel Dragomir <daniel.dragomir@windriver.com>
Signed-off-by: Quanyang Wang <quanyang.wang@windriver.com>
Signed-off-by: Liwei Song <liwei.song@windriver.com>