I would leave it, maybe mulch around the peas a little.
Let us know how it turns out.

That is one of the reasons why I've decided not to do any kind of cover crops - because you are basically filling your garden with seeds of weed or other things.

It certainly does help to introduce nitrogen into the soil - but if you don't till it in before it goes to seed, you'll have a mess on your hands.

Even then - the seed that doesn't sprout when you first sow it may come back in the spring time.

Here is a link that might be useful: My Garden Blog

I guess that's why they say never to plant crimson clover anywhere it isn't going to tilled in before maturity. White clover is for interplanting and between rows.

"Should I till the clover under or will the peas out grow it?"

IME you'd be better off pulling the clover back until the peas get well established. A similar situation happened (inadvertently) here when the wife planted legumes where I had sown buckwheat. The cover mostly choked everything else.