drm/amd/powerplay: Update CKS on/ CKS off voltage offset calculation.

As get the right evv voltage, update them to latest coefficients to
align with BB.

agd: squash in Slava's 32 bit build fix

Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>