x86/p2m: add option to skip root pagetable removal in p2m_teardown()

x86/p2m: add option to skip root pagetable removal in p2m_teardown()

Add a new parameter to p2m_teardown() in order to select whether the
root page table should also be freed.  Note that all users are
adjusted to pass the parameter to remove the root page tables, so
behavior is not modified.

No functional change intended.

This is part of CVE-2022-33746 / XSA-410.

Suggested-by: Julien Grall <julien@xen.org>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Tim Deegan <tim@xen.org>
master commit: 1df52a270225527ae27bfa2fc40347bf93b78357
master date: 2022-10-11 14:21:23 +0200