samples: ipc: ipc_service: show full board and target name

CONFIG_BOARD does not allow to distiguish between cores.

Signed-off-by: Piotr Kosycarz <[email protected]>

Author: nordic-piks

samples/ipc/ipc_service/src/main.c

@@ -101,7 +101,7 @@ int main(void)
 	p_payload->size = CONFIG_APP_IPC_SERVICE_MESSAGE_LEN;
 	p_payload->cnt = 0;
 
-	printk("IPC-service %s demo started\n", CONFIG_BOARD);
+	printk("IPC-service %s demo started\n", CONFIG_BOARD_TARGET);
 
 	ipc0_instance = DEVICE_DT_GET(DT_NODELABEL(ipc0));