I think it's Intel, although Qualcomm chips are being used in their CDMA variants of the iPhone. Apple uses Infineon baseband chips, however the company (Infineon) was bought out by Intel, hence it is Intel who supplies the offending chips.

Apple tried to pay Samsung for the license after Samsung revoked it (probably to get more money from Apple), but Samsung turned down the license fee claiming they wanted more.

To me, this sounded like Samsung wanted Apple to violate some of their patents for some ammunition in the case.

I don't think Apple willfully infringed anything here. They just bought chips from a manufacturer, assuming that they can use the chips they paid for in their products. It seems crazy someone could sell you chips, and then sue you if you happen to use them in your products.