Fixed missing function parameter in several function calls for `asd_from_freq_series`

Just to check I understand. The current calls to asd_from_frequency_series appear to only give one argument, but the function requires two. So I'm confused why any of these pass?

It may be better in the future to gave the difference between two frequencies as an attribute (this is in fact 1/duration). But, I'm happy to approve this for now and fix it at a later date.

approved this merge request

mentioned in commit c74659f4

merged

I am not sure why this passed, this should just fix it for now. We can eventually work on how we handle time- and frequency series in a more sophisticated way.