state: add fixup to copy state from barebox to kernel device tree
This patch registers a DT fixup, that copies the state nodes from the active
to the kernel DT. The backend reference will be a phandles.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>