[dv] Enable xcelium to include X for toggle coverage

Address #10332
Signed-off-by: Weicai Yang <weicai@google.com>
diff --git a/hw/dv/tools/xcelium/common.ccf b/hw/dv/tools/xcelium/common.ccf
index 2cfa7ba..b01c825 100644
--- a/hw/dv/tools/xcelium/common.ccf
+++ b/hw/dv/tools/xcelium/common.ccf
@@ -55,3 +55,6 @@
 
 // Enable scoring of FSM arcs (state transitions).
 set_fsm_arc_scoring
+
+// Include X->1|0 for toggle coverage collection. #10332
+set_toggle_includex