[dvsim] Fix testplan test counts
[dvsim] Fix testplan test counts

The same tests mapped to different testplan entries get
multiply-counted, resulting in incorrect totals. This update fixes that.

Signed-off-by: Srikrishna Iyer <2803d640feace36379942447842f26c7747b4dc3@google.com>

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