samples/drivers/mbox: Add run test for simulated target

Add a runtest for the simulated target.

Signed-off-by: Alberto Escolar Piedras <alberto.escolar.piedras@nordicsemi.no>

samples/drivers/mbox/sample.yaml

@@ -1,15 +1,26 @@
 sample:
   name: MBOX IPC sample
+common:
+  sysbuild: true
+  tags: mbox
 tests:
-  common:
-    sysbuild: true
-  sample.drivers.mbox:
+  sample.drivers.mbox.real_hw:
     platform_allow:
       - nrf5340dk_nrf5340_cpuapp
-      - nrf5340bsim_nrf5340_cpuapp
       - adp_xc7k_ae350
       - mimxrt595_evk_cm33
     integration_platforms:
       - nrf5340dk_nrf5340_cpuapp
-    tags: mbox
     harness: remote
+  sample.drivers.mbox.simu:
+    platform_allow:
+      - nrf5340bsim_nrf5340_cpuapp
+    harness: console
+    harness_config:
+      type: multi_line
+      ordered: false
+      regex:
+        - "Ping \\(on channel 0\\)"
+        - "Pong \\(on channel 0\\)"
+        - "Ping \\(on channel 1\\)"
+        - "Pong \\(on channel 1\\)"