Derive the value for template layer.conf from core layer and add
dependendency on it too.
Fixes [YOCTO #12767]
(From OE-Core rev: 461c305078c40fca8b5382e393e3e8513d4abfa4)
Signed-off-by: Anuj Mittal <anuj.mittal@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>