[stella/f26] (7 commits) ...Try fix build on ppc64le

Summary of changes: 5491122... git add stella-4.7.3-gcc7.patch (*) 2761ede... Add upstream patch (https://github.com/stella-emu/stella/is (*) 7cca506... Add another upstream patch, potential fix for compile failu (*) 6b45991... fix typo (*) edc62bb... Exclude arch ppc64 ppc64le. (*) ace7c7b... Author ask to build this: https://github.com/stella-emu/ste (*) e645b1f... Try fix build on ppc64le (*) (*) This commit already existed in another branch; no separate mail sent