make-bootstrap-tools-cross: add loongarch64-unknown-linux-gnu

Author: Aleksanaa

pkgs/stdenv/linux/make-bootstrap-tools-cross.nix

@@ -36,6 +36,7 @@ lib.mapAttrs (n: make) (
     powerpc64le-unknown-linux-gnu = powernv;
     riscv64-unknown-linux-gnu = riscv64;
     s390x-unknown-linux-gnu = s390x;
+    loongarch64-unknown-linux-gnu = loongarch64-linux;
 
     # musl
     aarch64-unknown-linux-musl = aarch64-multiplatform-musl;