What is the Autocorrelation of the Impulse Response if the Magnitude of Frequency Response is >1
Make sure not to confuse the power spectral density (PSD) with the frequency response. 


PSD is the Fourier transform of the autocorrelation function. 
Frequency response is the Fourier transform of impulse response.


That aside, your question is about the Fourier transform of a constant $c$.
Since $$\mathcal{F}\{1\}=\delta(\omega),$$
considering linearity of the Fourier transform we have $$\mathcal{F}\{(c)1)\}=(c)\delta(\omega)$$