scpi-pps: Add more HMP4000 series devices

scpi-pps: Add more HMP4000 series devices

List both vendor names "HAMEG" and "ROHDE&SCHWARZ" in the scpi-pps
driver, either responses were seen for HMP4000 devices. Unfortunately
vendor names don't support regex matches, so they require individual
profile items. The items also "violate" the alpha sort order in the list
of profiles, but keeping the series' models together is more important.

Add a declaration for the HMP4030 device which re-uses the HMP4040 data
but open codes the smaller channel count. Ideally the .probe_channels()
routine would receive the scpi_pps item as a parameter, and could yield
model specific result data from common information for the series. The
implementation in this commit is the least intrusive approach until
something better becomes available.

This shall cover the whole HMP4000 series:
  https://www.rohde-schwarz.com/product/hmp4000