Allow packages using llvm-config to find it using meson's dependency
interface.
(From OE-Core rev: e2e733c813e1eabaaff795a30b82e703dfeecfe7)
Signed-off-by: Anuj Mittal <anuj.mittal@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>