add mqttclient to the component, and add fire stm32f429 board demo.

components/connectivity/mqttclient/common/log/test/test.c

@@ -0,0 +1,24 @@
+/*
+ * @Author: jiejie
+ * @Github: https://github.com/jiejieTop
+ * @Date: 2019-12-26 20:00:29
+ * @LastEditTime : 2019-12-26 20:56:50
+ * @Description: the code belongs to jiejie, please keep the author information and source code according to the license.
+ */
+#include "salof.h"
+#include <stdio.h>
+#include <unistd.h>
+
+int main()
+{
+    salof_init();
+    
+    LOG_INFO("asfafasf");
+    sleep(1);
+    LOG_ERR("asfafasf");
+    LOG_WARN("asfafasf");
+    LOG_DEBUG("asfafasf\n");
+
+    sleep(1);
+}
+