[Bug Report]: esp32 micropython环境，lvgl初始化后，无法使用网络接口

### 联系方式

qiugang@wuhanxl.com

### 您发现了什么问题

esp32 Python轻代码框架，lvgl初始化后，调用wlan = network.WLAN(network.STA_IF)会报Memory allocation failed.
运行环境:ESP32 m5stackcore2
固件版本:[HaaSPython-ESP32-8M-v2.1.0](https://hli.aliyuncs.com/o/config/HaaS_Python/HaaSPython-ESP32-8M-v2.1.0.zip)

### 分支

rel_3.3.0 (Main)

### 请选择您发现此问题的解决方案名称

py_engine_esp32_demo

### 日志

```shell
>>> import lvgl as lv
>>> from display import LVGL as disp
>>> import network
>>> lv.init()
E (3477) disp_lvgl: app_init
>>> disp.init()
E (3687) disp_lvgl: register touch driver
>>> wlan = network.WLAN(network.STA_IF)

Memory allocation failed

Backtrace:0x40093dd1:0x3ffea9c0 0x400943bd:0x3ffea9e0 0x401aac3a:0x3ffeaa00 0x40085d93:0x3ffeaa20 0x40081c2d:0x3ffeaa50 0x401dd730:0x3ffeaa70 0x401d301a:0x3ffeaab0 0x401c27fe:0x3ffeaad0 0x401c288f:0x3ffeaaf0 0x401bfd0e:0x3ffeab10 0x401da0e2:0x3ffeab30

ELF file SHA256: 0000000000000000

Rebooting...
ets Jul 29 2019 12:21:46
```

Start with the py_engine_esp32_demo reproduction on the ESP32 M5Stack Core2 using HaaSPython-ESP32-8M-v2.1.0. Run the shown lvgl and display initialization before creating network.WLAN(network.STA_IF), then use the backtrace to locate the allocation failure. Done means WLAN creation no longer fails after LVGL initialization without regressing the display setup.

Written by the indexing model from the issue text.