Pull Xen bugfixes from David Vrabel:
- fix ARM build
- fix boot crash with PVH guests
- improve reliability of resume/migration
* tag 'stable/for-linus-3.17-b-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
x86/xen: use vmap() to map grant table pages in PVH guests
x86/xen: resume timer irqs early
arm/xen: remove duplicate arch_gnttab_init() function