refactor: sysroot部件化，prebuilts_lite_sysroot仓下线

close: #I5IJJE
Signed-off-by: Narvinzzz <zhaotianyu9@huawei.com>
Change-Id: Id587a018ff8b1e122848b9bd98922d64f9bf9d80

en/readme/kernel.md

@@ -211,8 +211,6 @@ LiteOS:
 
 [device\_qemu](https://gitee.com/openharmony/device_qemu/blob/master/README.md)
 
-[prebuilts\_lite\_sysroot](https://gitee.com/openharmony/prebuilts_lite_sysroot/blob/master/README.md)
-
 Linux:
 
 [kernel\_linux\_patches](https://gitee.com/openharmony/kernel_linux_patches/blob/master/README.md)

zh-cn/readme/内核子系统.md

@@ -222,8 +222,6 @@ LiteOS：
 
 [device\_qemu](https://gitee.com/openharmony/device_qemu/blob/master/README_zh.md)
 
-[prebuilts\_lite\_sysroot](https://gitee.com/openharmony/prebuilts_lite_sysroot/blob/master/README_zh.md)
-
 Linux：
 
 [kernel\_linux\_patches](https://gitee.com/openharmony/kernel_linux_patches/blob/master/README_zh.md)