fix(Dockerfile): add SHA256 checksum verification for LoongArch64 toolchain

docs: add LoongArch64 files to README

Author: ZR233

README.md

@@ -16,6 +16,9 @@ aarch64/shell.efi
 riscv64/vars.fd
 riscv64/code.fd
 riscv64/shell.efi
+loongarch64/vars.fd
+loongarch64/code.fd
+loongarch64/shell.efi
 ```
 
 [**Latest Release**](https://github.com/rust-osdev/ovmf-prebuilt/releases/latest)

build-edk2/Dockerfile

@@ -19,6 +19,7 @@ RUN tar -C /opt -xzf gcc-riscv.tar.gz
 
 # Use the LoongArch64 cross toolchain for building LoongArch64 code. 
 RUN wget https://github.com/loongson/build-tools/releases/download/2023.08.08/x86_64-cross-tools-loongarch64-binutils_2.41-gcc_13.2.0.tar.xz
+RUN echo "51f02e7e63e406892f1a6b7fae2a50c98758449358de67418d79acacda22b8e3  x86_64-cross-tools-loongarch64-binutils_2.41-gcc_13.2.0.tar.xz" | sha256sum --check
 RUN mkdir /opt/loongarch64_cross-toolchain/
 RUN tar -vxf x86_64-cross-tools-loongarch64-binutils_2.41-gcc_13.2.0.tar.xz -C /opt/loongarch64_cross-toolchain/