If you itemized your expenses instead of taking the standard deduction, you MAY Amend Your Return (click link for instructions) to enter the PMI. You will need to print and mail the 1040X and a copy of your new 1098. It will take approximately 10-14 weeks to for the IRS to process your additional refund. You can check the status by clicking here Where's My Amended Return
If you took the Standard Deduction or the difference between the Standard and Itemized deductions were less than your PMI, you will not need to do anything as this will not affect your return.