linux-image-unsigned-4.15.0-20-generic 4.15.0-20.21~16.04.1 (ppc64el binary) in ubuntu xenial

 This package contains the unsigned Linux kernel image for version 4.15.0 on
 PowerPC 64el SMP.
 .
 Supports Generic processors.
 .
 Geared toward desktop and server systems.
 .
 You likely do not want to install this package directly. Instead, install
 the linux-generic meta-package, which will ensure that upgrades work
 correctly, and that supporting packages are also installed.