Loading a load of json files into a memory structure and stashing in a bitbake
variable is relatively anti-social making bitbake -e output hard to read for
example as well as other potential performance issues.
Defer loading of that data until it is actually needed/used in a funciton
where it is now passed as a parameter.
(From OE-Core rev: 6f21cc9598178288784ff451ab3c40b174c0ef3e)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>