[otbn,dv] Call on_state_change with the correct value in scoreboard

Bug found by an Xcelium elaboration error (oops!)

Signed-off-by: Rupert Swarbrick <rswarbrick@lowrisc.org>
diff --git a/hw/ip/otbn/dv/uvm/env/otbn_scoreboard.sv b/hw/ip/otbn/dv/uvm/env/otbn_scoreboard.sv
index 1783cbc..6d14116 100644
--- a/hw/ip/otbn/dv/uvm/env/otbn_scoreboard.sv
+++ b/hw/ip/otbn/dv/uvm/env/otbn_scoreboard.sv
@@ -401,7 +401,9 @@
 
           model_status = item.status;
 
-          if (cfg.en_cov) cov.on_state_change(model_status);
+          if (cfg.en_cov) begin
+            cov.on_state_change(get_operational_state(status_e'(model_status)));
+          end
         end
 
         OtbnModelInsn: begin