Dear Shubham,
The .dvscf file contains part of the dV^KS/dU. One then have to add the Ewald terms and then take the sandwich with the wavefunctions.
The whole term <u|dV/du|u> is contained in the .epb files.
Note that in EPW we have it for <k+q|dV/du|k> so you will need to look at q=\Gamma only for this one.
Best wishes,
Samuel