Remove tree-like structure from AML. This allows more spec compliant
parsing of named objects inside not yet declared devices.
This also allows AML to be run thread safely. All object adds/removes
are now guarded by a mutex.
Now AML parsing is actually done while respecting namespaces and
scopes. I implemented the minimal functionality to parse qemu's AML.
Next step is to implement AML interpreting and then we can drop lai
as a dependency.
