ACPI: property: Allow making references to non-device nodes

Implement references to non-device nodes using the first package
entry in the hierarchical data extension reference, the second one
being the name of the referred object.

The data node references are parsed just after the device arguments
before the integer arguments. If there are no strings after the
device arguments, the parsing works exactly as it used to be.

Referring to a data node called "node" under device DEV, with
integer arguments 0, 2 would thus look like:

	Package() { DEV, "node", 0, 2 }

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