libyajl: Removal of addon as no longer required by libvirt

libyajl: Removal of addon as no longer required by libvirt

- libyajl is no longer being used by libvirt. libvirt now uses json-c which is a core
   package in IPFire. libyajl was stopped being used as it had not been updated and
   is considered effectively dead upstream.
- lfs, rootfile and libyajl entry in make.sh removed.

Signed-off-by: Adolf Belka <adolf.belka@ipfire.org>
Reviewed-by: Michael Tremer <michael.tremer@ipfire.org>
Signed-off-by: Arne Fitzenreiter <arne_f@ipfire.org>