qemu: split the native version into usermode and system parts
The rationale is to streamline the overall build.
The system parts are only needed to run target images, and so can be
built towards the end of the build process. At the same time, the
system parts may need gtk+-native and mesa-native which add significantly
to the build time.
On the other hand, the usermode parts have almost no dependencies
and can be built quickly. They are needed at recipes build time to
run target binaries, and so are required quite early in the typical
build process.
Signed-off-by: Alexander Kanavin <alex.kanavin@gmail.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
