Replace printf() with proper ESP_LOGx() (CA-137)

[liudr]

There are several printf() in the port folder. Here is one example: https://github.com/espressif/esp-azure/blob/90716c7b51aa499c2eeffa212039e18e98932fa0/port/src/agenttime_esp.c#L15 I recommend replacing them with appropriate ESP_LOGx() to help control log level. Especially if someone wants a clean console app and azure keeps printing out waiting for time etc.

Thanks.