In firmware we store the address to firmware blake2s() function at
TK1_MMIO_TK1_BLAKE2S so app can use this firmware function sort of
like a system call but without context switch.
We introduce an explicit state machine (see README).
With the new states we:
- combine setting size and USS to a single command.
- start the device app immediatiely when having receceived the last
data chunk and returning the digest.
- Loop forever and wait for the stick to be removed if we end up in
unknown state.
Signed-off-by: Michael Cardell Widerkrantz <mc@tillitis.se>
