libxl: support enabling the HPET
libxl: support enabling the HPET

libxl accepts hpet configuration in its domain info struct.  Parse the
domain definition's <clock> element in order to set the value.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Apologies from Eric Blake, for mistakenly committing the broken
intermediate version.

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