If you made a donation in exchange for a state tax credit and claimed itemize deductions on your Federal return, your Federal return charitable contribution deduction must be reduced as a result of receiving or expecting to receive this state tax credit.
In TurboTax:
I dont see a screen Adjustment to State Income Tax Deduction
Can you clarify if you are looking for the inputs for increased standard deduction for charitable contributions?
If so, the screen you are looking for is titled Additional Standard Deduction for Charitable Contributions. This is directly in the on-screen interview, following the screen Any other Subtraction Adjustments?