FROMLIST: ARM: xen: Register with kernel restart handler

Register with kernel restart handler instead of setting arm_pm_restart
directly.

Select a high priority of 192 to ensure that default restart handlers
are replaced if Xen is running.

Bug: 146512338
Change-Id: I1bfa30771cb3d1289177ba86b3378e3f6cd01e1c
Link: https://lore.kernel.org/patchwork/patch/1139627/


Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Thierry Reding <treding@nvidia.com>