schemas: Fix cpu element schema
schemas: Fix cpu element schema

Both vendor and topology elements are optional.

andreabolognani/libvirt,datto/libvirt,shugaoye/libvirt,jfehlig/libvirt,rbu/libvirt,libvirt/libvirt,sshah-solarflare/Libvirt-PCI-passthrough-,foomango/libvirt,taget/libvirt,shugaoye/libvirt,bjzhang/libvirt,fabianfreyer/libvirt,rmarwaha/libvirt1,jfehlig/libvirt,siboulet/libvirt-openvz,siboulet/libvirt-openvz,warewolf/libvirt,fabianfreyer/libvirt,olafhering/libvirt,jfehlig/libvirt,bjzhang/libvirt,olafhering/libvirt,jardasgit/libvirt,zhlcindy/libvirt-1.1.4-maintain,sshah-solarflare/Libvirt-PCI-passthrough-,rmarwaha/libvirt1,andreabolognani/libvirt,siboulet/libvirt-openvz,jeckersb/libvirt,bjzhang/libvirt,emaste/libvirt,iam-TJ/libvirt,danwent/libvirt-ovs,rlaager/libvirt,danwent/libvirt-ovs,rmarwaha/libvirt,andreabolognani/libvirt,bjzhang/libvirt,trainstack/libvirt,agx/libvirt,cbosdo/libvirt,trainstack/libvirt,foomango/libvirt,VenkatDatta/libvirt,andreabolognani/libvirt,dumbbell/libvirt,usc-isi/libvirt,novel/fbsd-libvirt,eskultety/libvirt,rlaager/libvirt,datto/libvirt,emaste/libvirt,emaste/libvirt,trainstack/libvirt,zippy2/libvirt,usc-isi/libvirt,rmarwaha/libvirt1,olafhering/libvirt,leilihh/libvirt,siboulet/libvirt-openvz,cbosdo/libvirt,crobinso/libvirt,VenkatDatta/libvirt,leilihh/libvirt,kantai/libvirt-vfork,jardasgit/libvirt,rmarwaha/libvirt,wiedi/libvirt,zippy2/libvirt,jfehlig/libvirt,crobinso/libvirt,elmarco/libvirt,dumbbell/libvirt,zippy2/libvirt,bjzhang/libvirt,eskultety/libvirt,leilihh/libvirt,cbosdo/libvirt,kantai/libvirt-vfork,jeckersb/libvirt,emaste/libvirt,wiedi/libvirt,fabianfreyer/libvirt,elmarco/libvirt,eskultety/libvirt,nertpinx/libvirt,rlaager/libvirt,emaste/libvirt,zhlcindy/libvirt-1.1.4-maintain,VenkatDatta/libvirt,usc-isi/libvirt,taget/libvirt,cbosdo/libvirt,leilihh/libvirt,iam-TJ/libvirt,rmarwaha/libvirt,sshah-solarflare/Libvirt-PCI-passthrough-,zhlcindy/libvirt-1.1.4-maintain,taget/libvirt,siboulet/libvirt-openvz,jeckersb/libvirt,VenkatDatta/libvirt,wiedi/libvirt,iam-TJ/libvirt,warewolf/libvirt,jardasgit/libvirt,usc-isi/libvirt,rbu/libvirt,novel/fbsd-libvirt,novel/fbsd-libvirt,olafhering/libvirt,jeckersb/libvirt,libvirt/libvirt,novel/fbsd-libvirt,zhlcindy/libvirt-1.1.4-maintain,iam-TJ/libvirt,emaste/libvirt,andreabolognani/libvirt,rbu/libvirt,danwent/libvirt-ovs,jeckersb/libvirt,rbu/libvirt,crobinso/libvirt,leilihh/libvirt,nertpinx/libvirt,dumbbell/libvirt,taget/libvirt,danwent/libvirt-ovs,shugaoye/libvirt,agx/libvirt,jeckersb/libvirt,warewolf/libvirt,nertpinx/libvirt,libvirt/libvirt,foomango/libvirt,datto/libvirt,warewolf/libvirt,cbosdo/libvirt,kantai/libvirt-vfork,nertpinx/libvirt,sshah-solarflare/Libvirt-PCI-passthrough-,datto/libvirt,rlaager/libvirt,danwent/libvirt-ovs,novel/fbsd-libvirt,eskultety/libvirt,foomango/libvirt,wiedi/libvirt,rbu/libvirt,agx/libvirt,soulxu/libvirt-xuhj,libvirt/libvirt,soulxu/libvirt-xuhj,shugaoye/libvirt,leilihh/libvirt,rmarwaha/libvirt1,iam-TJ/libvirt,dumbbell/libvirt,wiedi/libvirt,novel/fbsd-libvirt,kantai/libvirt-vfork,warewolf/libvirt,dumbbell/libvirt,rmarwaha/libvirt,sshah-solarflare/Libvirt-PCI-passthrough-,zippy2/libvirt,novel/fbsd-libvirt,fabianfreyer/libvirt,rmarwaha/libvirt1,foomango/libvirt,fabianfreyer/libvirt,VenkatDatta/libvirt,novel/fbsd-libvirt,agx/libvirt,trainstack/libvirt,usc-isi/libvirt,rmarwaha/libvirt,soulxu/libvirt-xuhj,iam-TJ/libvirt,elmarco/libvirt,wiedi/libvirt,nertpinx/libvirt,warewolf/libvirt,emaste/libvirt,warewolf/libvirt,datto/libvirt,trainstack/libvirt,elmarco/libvirt,taget/libvirt,wiedi/libvirt,novel/fbsd-libvirt,trainstack/libvirt,crobinso/libvirt,rmarwaha/libvirt1,zhlcindy/libvirt-1.1.4-maintain,jardasgit/libvirt,elmarco/libvirt,dumbbell/libvirt,eskultety/libvirt,soulxu/libvirt-xuhj,agx/libvirt,iam-TJ/libvirt,rmarwaha/libvirt,kantai/libvirt-vfork,jeckersb/libvirt,trainstack/libvirt,soulxu/libvirt-xuhj,jardasgit/libvirt,rlaager/libvirt,shugaoye/libvirt