oe/copy_buildsystem: move layer into layers directory
Layers could be located outside from poky but inside the build directory.
This case should be covered in eSDK.
meta-abc
meta-def/meta-ghi
meta-def/poky
meta-def/meta-oe/meta-oe
...
It should take all enabled layers and put them into 'layers' dir during
build-time with respecting new relative path to poky.
layers/meta-abc
layers/meta-ghi
layers/poky
layers/meta-oe/meta-oe
...
Signed-off-by: Andrej Valek <andrej.valek@siemens.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
