hey,
the right link is
http://releases.linaro.org/archive/14.11/components/toolchain/binaries/aarch64-linux-gnu/gcc-linaro-4.9-2014.11-x86_64_aarch64-linux-gnu.tar.xz
notice the ‘archive’ folder.
We tend to archive older releases eventually. Please be aware that you are looking at a release note which is almost 1.5 year old… We do not support any ubuntu based images right now.