Comment 1 for bug 1657767

Missing in linux-image-4.9.0-12-generic_4.9.0-12.13_amd64, moved to linux-image-extra-4.9.0-12-generic_4.9.0-12.13_amd64. Not sure which version this first changed, it is in linux-image-generic for 4.4 and 4.8 kernels though; so we're happy there.