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

components/connectivity/mqttclient/common/mbedtls/wrapper/entropy_hardware_alt.c

@@ -0,0 +1,41 @@
+/*
+ * @Author: jiejie
+ * @Github: https://github.com/jiejieTop
+ * @Date: 2020-01-11 02:04:49
+ * @LastEditTime : 2020-01-11 02:12:16
+ * @Description: the code belongs to jiejie, please keep the author information and source code according to the license.
+ */
+#include "mbedtls/entropy.h"
+#include "random.h"
+
+#if defined(MBEDTLS_ENTROPY_HARDWARE_ALT)
+
+static int mbedtls_get_random(unsigned char *buf, size_t len)
+{
+    int i, j;
+    unsigned long tmp;
+
+    for (i = 0; i < ((len + 3) & ~3) / 4; i++) {
+        tmp = random_number();
+
+        for (j = 0; j < 4; j++) {
+            if ((i * 4 + j) < len) {
+                buf[i * 4 + j] = (unsigned char)(tmp >> (j * 8));
+            } else {
+                break;
+            }
+        }
+    }
+
+    return 0;
+}
+
+int mbedtls_hardware_poll(void *data, unsigned char *output, size_t len, size_t *olen)
+{
+    mbedtls_get_random(output, len);
+    *olen = len;
+
+    return 0;
+}
+
+#endif