Move code that controls MDIO speed into a new function because
there will be more MACs that need the control.
Signed-off-by: NMark Rustad <mark.d.rustad@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>