You can... but it is not a good idea.
It hash rate... is less than low.
Use your RbPi as controler (or computer) for you ASIC´s.
It is great for that.
If you need an OS for it check this:
https://bitcointalk.org/index.php?topic=137934.0;topicseenI forgot, try a power USB hub for your ASIC´s.
Good luck.