Add LOONGARCH64 architecture to ShellPkg for EDK2 CI testing.
Cc: Ray Ni <ray.ni@intel.com> Cc: Zhichao Gao <zhichao.gao@intel.com> Signed-off-by: Chao Li <lichao@loongson.cn> Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com> Reviewed-by: Zhichao Gao <zhichao.gao@intel.com>