[otbn,dv] Increase "size" parameter for gen-binaries.py
[otbn,dv] Increase "size" parameter for gen-binaries.py

The setup and teardown for these tests takes way longer than the
instructions themselves. Try to rebalance a little bit.

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

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