baremetal-helloworld: Move from skeleton to recipes-extended matching what...

baremetal-helloworld: Move from skeleton to recipes-extended matching what rust-hello-world is doing

Signed-off-by: Alejandro Enedino Hernandez Samaniego <alejandro@enedino.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>