feat: add back support for 2k1000la board

[AsakuraMizu]

Description

Add basic support for 2k1000la physical board back.

This work is thanks to @Blankke's exceptional skills and hard work!

[Copilot]

Pull request overview

This PR restores support for the Loongson 2K1000LA physical board by adding the necessary build configuration, dependencies, and platform-specific integration.

• Adds the 2k1000la feature flag and corresponding platform dependency
• Creates a new Makefile target with LoongArch64-specific compiler flags
• Updates the submodule reference to include 2K1000LA support
• Integrates the platform crate in the main entry point

Reviewed changes

Copilot reviewed 4 out of 5 changed files in this pull request and generated 1 comment.

File	Description
src/main.rs	Adds conditional compilation for the 2K1000LA platform crate
arceos	Updates submodule commit to version with 2K1000LA support
Makefile	Adds new build target for 2K1000LA with architecture-specific flags
Cargo.toml	Configures feature flag, dependencies, and SMP support for 2K1000LA

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[AsakuraMizu]

TODO

1. https://github.com/Starry-OS/simple-ahci uses DMA and that has a requirement on buffer alignment. Previous effort to fix this has some problems, notably allocating a new buffer every time. Some buffer reuse must be implemented (maybe pre-allocation or a slab). In the long run, we may need something like virtio_drivers::Hal. After this we may release it on crates.io.
2. Split LoongArch IRQ chip related stuffs into a separate crate. Current code exists in: https://github.com/arceos-org/axplat_crates/tree/dev/platforms/axplat-loongarch64-qemu-virt/src/irq and https://github.com/LoongsonLab/axplat-loongarch64-2k1000la/tree/main/src/irq.
3. There are still some way to go before https://github.com/LoongsonLab/gmac_driver/ can be merged, notably https://github.com/LoongsonLab/gmac_driver/blob/master/src/platform.rs which uses a lot of extern "C" functions and is clearly a legacy from the previous c2rust. We need to make it more Rust style.