This variable is a performance liability and is highly dependent on which
layers are added to the configuration which can cause signature issues
for users. We have no users left in OE-Coreso remove it.
(From OE-Core rev: bf08d9ccb9cbc749a571af3d33140bcae0e252a6)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>