Removed references to BlueGene/Q in Spack builtin packages

var/spack/repos/builtin/packages/apple-libunwind/package.py

var/spack/repos/builtin/packages/charmpp/package.py

var/spack/repos/builtin/packages/elpa/package.py

var/spack/repos/builtin/packages/elsi/package.py

var/spack/repos/builtin/packages/hpctoolkit/package.py

var/spack/repos/builtin/packages/lcals/package.py

var/spack/repos/builtin/packages/libglvnd/package.py

var/spack/repos/builtin/packages/libmonitor/package.py

var/spack/repos/builtin/packages/llvm/package.py

var/spack/repos/builtin/packages/neuron/package.py

var/spack/repos/builtin/packages/py-matplotlib/package.py

var/spack/repos/builtin/packages/py-tensorflow/package.py

var/spack/repos/builtin/packages/scorec-core/package.py

var/spack/repos/builtin/packages/scotch/package.py

var/spack/repos/builtin/packages/scr/package.py

var/spack/repos/builtin/packages/tau/package.py