ich9: fix skipped vmstate_memhp_state subsection

By declaring another .subsections array for vmstate_tco_io_state made
vmstate_memhp_state not registered anymore. There must be only one
.subsections array for all subsections.

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Amit Shah <amit.shah@redhat.com>
Reported-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NPaulo Alcantara <pcacjr@zytor.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: NAmit Shah <amit.shah@redhat.com>

hw/acpi/ich9.c

@@ -206,9 +206,6 @@ const VMStateDescription vmstate_ich9_pm = {
     },
     .subsections = (const VMStateDescription*[]) {
         &vmstate_memhp_state,
-        NULL
-    },
-    .subsections = (const VMStateDescription*[]) {
         &vmstate_tco_io_state,
         NULL
     }