[otbn,dv] Fix parsing of CMD writes in scoreboard
[otbn,dv] Fix parsing of CMD writes in scoreboard

The CMD register only contains an 8-bit field, so we should ignore the
upper 24 bits when deciding what value was written.

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

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