I cant upgrade Ubuntu mate 16.04.5 to 18.10 in my PowerMac G5

[Towersen]

Perhaps, the system not recognize my PowerPC processor for upgrade it.

System Spec:
Processor: PPC970FX, altivec supported × 2
Memory: 4GB
Video: Nvidia Geforce 5200 ultra (AGP pro)

Versión 16.04.5 LTS (Xenial Xerus) de 32-bit
Núcleo Linux 4.4.0-131-powerpc64-smp ppc64
MATE 1.12.1

Thanks you for support for all G5 users community!!!

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: ubuntu-release-upgrader-core 1:16.04.25
ProcVersionSignature: Ubuntu 4.4.0-131.157-powerpc64-smp 4.4.134
Uname: Linux 4.4.0-131-powerpc64-smp ppc64
ApportVersion: 2.20.1-0ubuntu2.18
Architecture: powerpc
CrashDB: ubuntu
Date: Mon Jul 30 12:06:48 2018
InstallationDate: Installed on 2018-07-15 (15 days ago)
InstallationMedia: Ubuntu-MATE 16.04.1 LTS "Xenial Xerus" - Release powerpc (20160719)
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=es_ES
 PATH=(custom, no user)
 LANG=es_ES.UTF-8
 SHELL=/bin/bash
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to xenial on 2018-07-30 (0 days ago)
VarLogDistupgradeAptlog:
 Log time: 2018-07-30 12:04:39.025368
 Log time: 2018-07-30 12:04:46.162522
 Log time: 2018-07-30 12:05:39.691231
 Log time: 2018-07-30 12:06:54.106466
VarLogDistupgradeTermlog:

mtime.conffile..etc.update-manager.release-upgrades: 2018-07-15T07:07:42.599556

[Adam Conrad (adconrad)]

Big-endian PowerPC support was dropped after 16.10. There is no upgrade path from 16.04.5, however it will be supported for another ~3 years.

If this bug is about update-notifier telling you there's an upgrade when there isn't one, that's entirely valid and should be looked at...