Added MS/TP automatic baudrate detection option into the core MS/TP state machine. (#900)

test/bacnet/basic/sys/test/mstimer_mock.c

@@ -0,0 +1,20 @@
+/**
+ * @file
+ * @brief Stub functions for unit test of a BACnet object
+ * @author Steve Karg <skarg@users.sourceforge.net>
+ * @date January 2025
+ * @copyright SPDX-License-Identifier: MIT
+ */
+#include <zephyr/ztest.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include "bacnet/basic/sys/mstimer.h"
+
+/**
+ * @brief Get the current time in milliseconds
+ * @return milliseconds
+ */
+unsigned long mstimer_now(void)
+{
+    return ztest_get_return_value();
+}