Revert "qemu: allow to build host variant statically"

Revert "qemu: allow to build host variant statically"

This reverts commit a6afa968fc9080080b943885b8599475df9e36c4, which
causes too many different build issues:

  http://autobuild.buildroot.net/results/d5c/d5ced6c9738b285e6fda8c3d41c3c66ee0cf1edc/build-end.log

  http://autobuild.buildroot.net/results/fca/fca01cc5ce13384df0a7f8fad75e2acd05598f99/build-end.log

  http://autobuild.buildroot.net/results/f17/f1755f26a3eacd84de9bd901b214a5bbb964988c/build-end.log

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>