state: backend: support phandle and of_path references ...

This patch improves the backend property, it can be either a phandle or a
of_path. During probe() of the state driver the backend property is
dereferenced and the resulting of_path is saved in the state context. In a
later patch it will be used to generate a phandle reference to the backend
during DT fixup.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

of_path: of_find_path(): add possibility to return .bb device ...

This patch adds a flags argument to the of_find_path() function. The only flag
defined for now is OF_FIND_PATH_FLAGS_BB. When used on NAND devices, the
function returns the bad block aware device (the ".bb" device).

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

state: add framework for persistent state handling ...

This patch adds a framework to describe, access, store and restore a set of
variables. A state variable set can be fully described in a devicetree node.
This node could be part of the regular devicetree blob or it could be an extra
devicetree solely for the state. The state variable set contains variables of
different types and a place to store the variable set.

For more information see:
    Documentation/devicetree/bindings/barebox/barebox,state.rst

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Jan Luebbe <jlu@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>