DTS format for direct SGMII TSEC link?

Hello,
I am working with a Freescale 8572 board which uses direct SGMII
connections (no real PHY) for three of the four TSECs.  I have been
trying to figure out the appropriate DTS elements to set this up, but
haven't yet managed to figure it out.  Everything works great in
u-boot, so I know that the connections & hardware are functional.
I've tried setting up dummy physical phys, using only the tbi-phy, and
using the 'fixed-link' property, none of which have achieved the
desired result.
I realize I'm taking the lazy way out by not digging into the gianfar
code, but I was hoping that this problem had already been seen and
addressed and could be handled with the right text in the DTS file.

Thanks,
Aaron Pace