Pull xen updates from Juergen Gross:
"Only two minor patches this time: one cleanup patch and one patch
refreshing a Xen header"
* tag 'for-linus-5.14-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen: sync include/xen/interface/io/ring.h with Xen's newest version
xen: Use DEVICE_ATTR_*() macro