Enable platform specific allocations and ram quota accounting for
protection domains. Needed to allocate object identity references
in the base-hw kernel when delegating capabilities via IPC.
Moreover, it can be used to account translation table entries in the
future.
Ref #1443
This patch changes the top-level directory layout as a preparatory
step for improving the tools for managing 3rd-party source codes.
The rationale is described in the issue referenced below.
Issue #1082