The 8544 DS has an optional SGMII Riser card, which uses different PHY
addresses.  Check if we are in SGMII mode, and invoke the SGMII Riser
setup code if so.
Signed-off-by: NAndy Fleming <afleming@freescale.com>
Signed-off-by: NBen Warren <biggerbadderben@gmail.com>