add cmsis3 dsp lib

This adds the CMSIS3 dsp library to all f3 and f4 targets as well as simulation.

For simulation i made a stripped down copy of the core_cm0.h file and called it core_sim.h.
I am not 100% happy with where to put that file as there is no PiOS.sim.
Maybe @solidgoldbomb has an idea.

Also i had to fix some pointer arithmetics which i am not 100% sure that its done correctly.

Another thing to consider is the granularity which this lib could be configured at target level.
Currently it builds everything for every target. This gives full control but adds some compile time. I see three options with this:
* build a library archive file for each architecture (f1, f3, f4, sim)
* add configuration to target makefile to enable building of specific features
* keep it as i have done

@kenz: please test this against your vibration module (in simulation if possible)