pkg: remove xen-devel for aarch64
pkg: remove xen-devel for aarch64

Disable xen-devel since it just got available for aarch64 in Fedora 25.

Signed-off-by: Anders Roxell <b4e8e89057bc64bc4f9625a4a821c9ac177a7ed2@linaro.org>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk