add easyconfigs for gimkl 1.5.9 toolchain and HPL with that toolchain

depends on https://github.com/hpcugent/easybuild-framework/pull/987 and https://github.com/hpcugent/easybuild-framework/pull/989
Does this mean that the deps won't get loaded? Or is the Toolchain block special? (too lazy to look it up :wink: )