There are two device IDs changed from 15C6/15C7 to 15E4/15E5 because of
PHY info changes. 15C6/15C7 IDs are now used for the backplane
SGMII versions.
Also, clean up some discovery kludges from the previous shared ID,
and also add 15C6/15C7 to ixgbe_set_mdio_speed just for paranoia
to control MDIO speed even though nothing should be attached.
Signed-off-by: Beilei Xing <beilei.xing@intel.com>
f2a5f0b8ee