[yocto] How to deal with non-standard license.

[Diego]

Hi everybody,

I have written a recipe which I'd like to contribute for glmark2:
https://launchpad.net/glmark2

The last thing that puzzles me before submitting it is that it's partly GPL3+, 
and partly under this license:
https://github.com/rafalmiel/glmark2-wl/blob/master/COPYING.SGI
which is not in this list:
https://wiki.yoctoproject.org/wiki/License_Infrastructure_Interest_Group#Licenses 
Is there any way to deal with that license? What should I put in the LICENSE 
field in my recipe?

Bests,
Diego