I'm not aware of any control surface support in PP.
I don't think there is any mixer that would supported by Premiere. However the sound card that does have some kind of mixer input will work with premiere
I have Asus Zonar sound card that has a mike input and line input and midi input as well. so any of those inputs work with premiere and midi input works as well, if it enabled. Currently it is disabled in sound card and not shown on screen shot. Perhaps that would give you some Ideas where to look for.