document the ProDe function unit hardware operation dialog

[Pekka Jääskeläinen]

One of the trickier parts of TTA customization in TCE is editing the function unit and its pipeline and I/O resource usage. This should be documented using screenshot examples of a fully pipelined and "complex resource usage" scenarios (e.g. the MIPS R4000 FPU model) to the user manual.

Also 1-latency is often confused with "latency 0" which is the common way to count the latencies (in our case we count clock edges, in the usual case they count full instruction cycles).

[Pekka Jääskeläinen (pekka-jaaskelainen)]

This is good enough. Screenshots would be nice but not mandatory.