I thought I read somewhere that they were going to cut him off around 150?
If so, that's news to me. Haven't heard anything like that before.
A quick Google search for Michael Pineda innings limit didn't bring anything of relevance either.
If he's healthy, which by all accounts he is, it'd be near impossible to shut him down until September, when rosters expand.
You can't send him down, and he can't be IL'd if he's healthy and pitching well. And you obviously can't carry him on the active roster if he isn't going to pitch.
Moving him to the bullpen could be an option, but you'd have to do it immediately. Even one more start would make it pretty tough to keep his innings under 150.