[dv] Switch cip_base_scoreboard logging to convert2string
[dv] Switch cip_base_scoreboard logging to convert2string

This changes the output format to a single line, which should be
easier to grep.

Signed-off-by: Rupert Swarbrick <290093e2ad2515ed2f14d749293c8cf8e02ca274@lowrisc.org>

lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan