korad-kaxxxxp: add quirks flags to table of supported models

korad-kaxxxxp: add quirks flags to table of supported models

Out of the current set of supported models, the Velleman LABPS3005D is
the only device which requires special OVP enable handling. In future
implementations, more quirks could get identified or other models could
be affected. Add a quirks flags field to the models[] table, so that
other driver code paths need not care about individual models.

This commit only provides the flag. Calling code is not adjusted in this
commit, to reduce the diff size and simplify review. There are a lot of
"no quirks" additions in this commit already.