ACPI: property: Update documentation for hierarchical data extension 1.1

Hierarchical data extension 1.1 allows using references as the second
entries of the hierearchical data extension packages. Update the
references and the examples.

The quotes are left in documentation for clarity.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>