For S390 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:tiwai:bsc1248121-3/S390/home:tiwai:bsc1248121-3.repo
zypper refresh
zypper install kernel-default
For PPC run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:tiwai:bsc1248121-3/PPC/home:tiwai:bsc1248121-3.repo
zypper refresh
zypper install kernel-default
For ARM run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:tiwai:bsc1248121-3/ARM/home:tiwai:bsc1248121-3.repo
zypper refresh
zypper install kernel-default