powerpc/64s/idle: Fix restore of AMOR on POWER9 after deep sleep

powerpc/64s/idle: Fix restore of AMOR on POWER9 after deep sleep

[ Upstream commit c1b25a17d24925b0961c319cfc3fd7e1dc778914 ]

POWER8 restores AMOR when waking from deep sleep, but POWER9 does not,
because it does not go through the subcore restore.

Have POWER9 restore it in core restore.

Fixes: ee97b6b99f42 ("powerpc/mm/radix: Setup AMOR in HV mode to allow key 0")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>