In the Personal Info section of Turbotax, enter your State of Residence as PA. Answer "No" to the question about living in another state. Under "Other State Income" enter TN. Then enter your W2 as is.
TT will generate a PA tax return. There'll be no TN tax return because TN has no state income tax. There'll be no "double taxation."
**Answers are correct to the best of my ability but do not constitute tax or legal advice.