x86/xen: remove 32-bit pv leftovers

There are some remaining 32-bit pv-guest support leftovers in the Xen
hypercall interface. Remove them.

Signed-off-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20211028081221.2475-2-jgross@suse.com


Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>