acpi nvdimm: fix OperationRegion definition

Based on ACPI spec:
 RegionOffset := TermArg => Integer

However, Named object is not a TermArg.

This patch moves OperationRegion to NCAL() and uses localX as
its RegionOffset

Suggested-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
