That motherboard is based on an NVidia SLI chipset; you can't mod it for Crossfire. An older system is Crossfire or SLI ready if it's based on a compatible chipset and the BIOS supports it. Crossfire and/or SLI compatibility usually is indicated in the motherboard or system specifications.
No by default you can not use crossfire on an nvidia based board. This is really just a driver limitation. I red about a hacked driver to allow it a few years back but I could not find the link. I have a feeling all work on that went away, because all the modern intel based boards support both CF and SLI