Create "ProcessManager" and "Domain" capabilities.

Create "ProcessManager" and "Domain" capabilities.

The ProcessManager capability is created by the CPU driver at startup and given
to init, where it will be passed on to the monitor and then the process manager
subsequently.

The Domain capability is an ID-like cap retypeable from the ProcessManager cap
above. The process management server can hence use the ProcessManager cap to
create Domain caps and give them to spawnd instances, to facilitate identifying
domains locally and globally.

Signed-off-by: Razvan Damachi <razvan.damachi@gmail.com>