[bazel] cleanup `verilator_params()` in `opentitan_functests()`
[bazel] cleanup `verilator_params()` in `opentitan_functests()`

The `verilator_params()` macro was refactored in a prior commit, but its
invocations in `opentitan_functest()` rules were not. This cleans these
up to remove un-needed (required) tags.

Signed-off-by: Timothy Trippel <77eacc84f9735d3cbb55a271710be269fc3a5818@google.com>

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