distrodata.bbclass: Include PRSPV variable in upstream version checking
The PRSPV variable is used for the packages that have different
representation for a same upstream and local version (e.g 2.0 vs 20).
In this case, the system is using PRSPV instead of PV when comparing
the local and upstream versions.
The packages that are using this modification are the following:
* zip
* unzip
* docbook-sgml-dtd-3.1-native
* docbook-sgml-dtd-4.1-native
