Mostly, a more expensive cell phone.
With all the features that smartphones offer (syncing with your computer to function like an MP3 player, apps like Pandora, full internet access) there’s no reason to need FM radio with its commercials, talk shows, and lack of direct interaction (seeding a Pandora station with your favorite band, going directly to the song you want to hear, getting a recommendation from someone with similar taste on Twitter or Facebook).
An FM chip will, however, cost more, even if you don’t want it/never use it, take up room in the phone–creating a limitation on possible future technologies–and would be the result of an unnecessary law (something no one ever really needs); there are already phones with FM chips available for those interested.
So what to do? Advocate to your representatives that you oppose it. If it does pass, you can always avoid paying the increased cost by choosing among used cell phones or refurbished cell phones. Refurbished cell phones offer an environmentally friendly option that saves you money.