ACPICA: Add support to delete all objects attached to the root namespace node.

This fix deletes any and all objects that have been attached to the
root node (via acpi_attach_data). Reported by Tomasz Nowicki.
ACPICA BZ 1026.

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>