[Bug] lab2 内存空间不足

[my-vegetable-has-exploded]

Describe the bug lab2 中rcore/os4/src/config.rs，

疑似内存大小不足，导致TaskControlBlock初始化内存分配失败。

此处 panic

将默认默认参数调大可以解决该问题。

To Reproduce make test4

Expected behavior A clear and concise description of what you expected to happen.

Screenshots

Environment (please complete the following information):

• OS: Ubuntu 20.04
• Rust Version: rustc 1.65.0-nightly (cf9ed0dd5 2022-09-15)
• QEMU Version: qemu-img version 7.0.0

Additional context if needed， i can open a pr to solve it.