Fix parameter order for VAM/IAM SPICE sources

This fixes the parameter order for the VAM/IAM spice sources. The modulation frequency and carrier frequency parameters were swapped from the general expectation that carrier frequency is higher than modulation frequency.

The correct order is amplitude, offset, modulation frequency, carrier frequency, signal delay, phase (with some nuances discussed in the below issue, which are not relevant here). Phase defaults to 0 so it's ok that it's left off below.

See discussion here: kicad/code/kicad#16529 (closed)

---

• Remove the instructional content of this template
• Provide a URL to a datasheet for the symbol(s) you are contributing
• An example screenshot image is very helpful
• Ensure that the associated footprints match the official footprint library
  • A new fitting footprint must be submitted if the library does not yet contain one.
• If there are matching footprint PRs, provide link(s) as appropriate
• Check the output of the automated check scripts - fix any errors as required
• Give a reason behind any intentional library convention rule violation.