Pull xen update from Juergen Gross:
 "Only two small patches this time:

   - a small cleanup for swiotlb-xen

   - a fix for PCI initialization for some platforms"

* tag 'for-linus-5.4-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/pci: reserve MCFG areas earlier
  swiotlb-xen: Convert to use macro