BrainScaleS: Update software state

This pulls in a few backported build changes that enables building on
non-x86 architectures.
This update introduces compile-time switches to disable building parts
of the low-level software stack which can be skipped for EBRAINS
operation; in particular, the communication modes for non-quiggeldy (the
experiment service) communication with the neuromorphic system are
now disabled conditionally.