When pursuing Public Service Loan Forgiveness, you do have the option to make lump sum payments for the 12 month period that your IDR plan has been approved for, but you cannot make extra payments to qualify you for forgiveness sooner. In other words, the expected date of forgiveness will never be sooner than your original estimate.
In the past, lump sum payments did not count toward PSLF but recent changes in administrative policy have made this a possibility. Please feel free to read THIS ARTICLE about lump sum payments from the Federal Student Aid website for more information. You can email firstname.lastname@example.org with any questions.