Many Linguistics MA programs do admit students who do not have a degree in linguistics or related fields. I've seen students majoring in chemistry and engineering getting in. What matters to your application is that you provide a good writing sample and statement of purpose, which demonstrates your understandings and interests in this field. Given that you have good GPA, TOEFL, and GRE, your chances could be high. But remember, scores are always secondary to your understandings, interests, as well as future plans to enter the academia.
Hope it helps! Good luck!