Comment # 1 on bug 1118048 from Michal Srb

Your guess is quite correct. The xf86-video-ati, xf86-video-mach64 and
xf86-video-r128 have:

  Supplements: modalias(xorg-x11-server:pci:v00001002d*sv*sd*bc03sc*i*)

So they are recommended every time there is a PCI device with vendor 1002 (AMD)
and base class 03 (video controller).

The libvdpau_r600, libvdpau_r300 and libvdpau_radeonsi Supplement the
xf86-video-ati package, so they are recommended when the xf86-video-ati is.

We could instead use multiple modalias lines listing the individual device IDs
that are handled by the specific driver, but it is error-prone and a
maintenance burden. I personally don't think it is worth it. The packages are
quite small and X server won't use them if you don't have the GPU.

You can also disable recommended packages in /etc/zypp/zypp.conf, but I would
not recommend that.