Compatibility with Flowdeck 1.0

[Coraku]

Hey, thanks for sharing the firmware!
Im currently testing it on a Crazyflie 2.1 pared with a Flowdeck 1.0
I built both directly in the repo, and in exaples/controller_tinympc. Both seem to work, but hovering them lets them fly into the ceiling.
Also, when i connect with the cf-client, I cant choose an Assist-mode.

I wanted to know, If the installation process was right, and what i had to do, if i wanted to let the drone hover.

Best Regards