grrr. I forgot they compiled it into the kernel now..
try this instead.
as root, edit your /boot/grub/grub.conf file
at the end of the kernel line append this:
I don't think you have to run dracut to create a new initramfs for this, but if you do:
cp /boot/initramfs-$(uname -r).img initramfs-$(uname -r).bak
dracut -f /boot/initramfs-$(uname -r).img $(uname -r)