[otbn,dv] Remove verilator workaround
[otbn,dv] Remove verilator workaround

The mis-firing WIDTH check that this was working around was fixed in
Verilator 2.104. Since we require 4.210, there's no need to keep it
in.

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

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