No you do not need to delete it. If you already entered it, just leave it. It will have no effect on your federal refund and could even help on your state return.
The information flows from your federal return to your state return.
The following states allow you to itemize deductions on just the state return: Alabama, Arizona, Arkansas, California, Delaware, Hawaii, Idaho, Iowa, Kentucky, Minnesota, Mississippi, Montana, New York, North Carolina, Oregon, and Wisconsin,