Comment # 8 on bug 1087261 from Takashi Iwai

OK, so you used to have drm-kmp installed for the older kernels, too.

Then, uninstall the latest drm-kmp once:
  zypper rm drm-kmp-default-4.9.33_k4.4.120_45-10.2.x86_64

And install kernel-default-4.4.120 again:
  zypper in --no-recommends kernel-default-default-4.4.120

... and get the drm-kmp-default.rpm from below and install it:
 
http://download.opensuse.org/repositories/home:/tiwai:/branches:/openSUSE:/Leap:/42.3:/Update/openSUSE_Leap_42.3_Update/

Rebuild initrd once, to be sure:
  mkinitrd

and retest.