We re-use the OpenEmbedded / Yocto Project style to
declare the licenses more prominently in the top level folders.

LICENSE is derived from poky's LICENSE file.

Bug-AGL: SPEC-3295
Signed-off-by: Jan-Simon Moeller <jsmoeller@linuxfoundation.org>
Change-Id: I7af49624b301a956f87191a07d39fcba6bbaa93c