No /dev/fpga0 device?

Hi, I compiled several Linux kernels 3.17.0 for a Cyclone V board, actually they're running, but now I don't see a /dev/fpga0. As this comes out-of-the-box with the default SD-card image (kernel 3.12.x),

I wonder what I did wrong? Any ideas, e.g. which option I may check in the kernel configuration?