from devices connected to pckbc:
- Do actual sample collection in pckbc.
- Add rndsource_element_t to the slot data.
- Change pckbc_set_inputhandler() to take an additional argument,
the name of the device, which is (eventually) passed into
rnd_attach_source() to identify the source.
- Change callers of pckbc_set_inputhander() appropriately.
timeout()/untimeout() API:
- Clients supply callout handle storage, thus eliminating problems of
resource allocation.
- Insertion and removal of callouts is constant time, important as
this facility is used quite a lot in the kernel.
The old timeout()/untimeout() API has been removed from the kernel.
